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Kang P, Zhang X, Jing X, Zhang L, Shen C, Gu B, Huang J, Wang Y, Li L, Lu Z. High average output power, dual-wavelength synchronously self-mode-locked Ho:LLF laser operating at 2068.5 and 2069.2 nm. OPTICS LETTERS 2024; 49:3316-3319. [PMID: 38875609 DOI: 10.1364/ol.527220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 05/15/2024] [Indexed: 06/16/2024]
Abstract
A dual-wavelength synchronously self-mode-locked Ho:LLF laser operating at 2068.5 and 2069.2 nm was demonstrated. The maximum average output power was as high as 2.6 W with a pulse repetition frequency of 3.03 GHz. Meanwhile, the output power ratio of the dual-wavelength lasers can be effectively controlled by varying the incident pump power. To the best of our knowledge, this is the first dual-wavelength synchronously self-mode-locked Ho-doped fluoride solid state laser; moreover, our current experimental results represent the highest average output power from a GHz self-mode-locked oscillator in the 2 µm wave band.
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Zhou X, Mao J, Hu P, Li J, Zhang J, Nie H, Li T, Feng T, Zhang B, He J, Yang K. 4.1 W continuous-wave and broadly wavelength tunable Tm-doped laser in 2.1-2.4 µm spectral region based on vibronic and electronic transitions. OPTICS EXPRESS 2024; 32:17028-17037. [PMID: 38858895 DOI: 10.1364/oe.521454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 04/08/2024] [Indexed: 06/12/2024]
Abstract
Efficient diode-pumped continuous-wave (CW) and wavelength tunable Tm:YAP lasers based on the vibronic and electronic transitions are investigated. A total maximum output power of 4.1 W is achieved with multi-wavelength output around 2162 nm and 2274 nm, corresponding to a slope efficiency of 29.8% for a 3 at. % Tm:YAP crystal. A maximum output power of 2.48 W with a slope efficiency of 25.4% is obtained at 2146 nm for a 4 at. % Tm:YAP crystal. Using a birefringent filter (BF), the emission wavelengths of the Tm:YAP laser are tuned over spectral ranges of 59 nm from 2115 nm to 2174 nm and 127 nm from 2267 nm to 2394 nm, respectively, which is the first demonstration of wavelength tunable Tm:YAP laser based on the electronic transition 3H4→3H5 and vibronic transition 3F4→3H6, to the best of our knowledge. The results show great potentials of the Tm:YAP crystal for realizing efficient lasers in the spectral range of 2.1-2.4 µm.
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3
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Tyazhev A, Bae JE, Gaulke M, Loiko P, Heidrich J, Golling M, Idlahcen S, Guillemot L, Godin T, Camy P, Keller U, Hideur A. Upconversion-pumped femtosecond thulium laser at 2309 nm mode-locked by a GaSb-based SESAM. OPTICS EXPRESS 2024; 32:15093-15105. [PMID: 38859168 DOI: 10.1364/oe.516958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 02/28/2024] [Indexed: 06/12/2024]
Abstract
We report on a femtosecond thulium laser operating on the 3H4 → 3H5 transition with upconversion pumping around 1 µm and passively mode-locked by a GaSb-based SEmiconductor Saturable Absorber Mirror (SESAM). This laser employs a 6 at.% Tm:LiYF4 laser crystal and a polarization maintaining Yb-fiber master oscillator power amplifier at 1043 nm as a pump source addressing the 3F4 → 3F2,3 excited-state absorption transition of Tm3+ ions. In the continuous-wave regime, the Tm-laser generates 616 mW at ∼2313 nm with a slope efficiency of 10.0% (vs. the incident pump power) and a linear polarization (π). By implementing a type-I SESAM with a single ternary strained In0.33Ga0.67Sb quantum well embedded in GaSb for sustaining and stabilizing the soliton pulse shaping, the self-starting mode-locked Tm-laser generated pulses as short as 870 fs at a central wavelength of 2309.4 nm corresponding to an average output power of 208 mW at a pulse repetition rate of 105.08 MHz and excellent mode-locking stability. The output power was scaled to 450 mW at the expense of a longer pulse duration of 1.93 ps. The nonlinear parameters of the SESAM are also reported.
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Tamer I, Hubka Z, Kiani L, Owens J, Church A, Batysta F, Galvin T, Willard D, Yandow A, Galbraith J, Alessi D, Harthcock C, Hickman B, Jackson C, Nissen J, Tardiff S, Nguyen H, Sistrunk E, Spinka T, Reagan BA. Demonstration of a 1 TW peak power, joule-level ultrashort Tm:YLF laser. OPTICS LETTERS 2024; 49:1583-1586. [PMID: 38489456 DOI: 10.1364/ol.519542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 02/27/2024] [Indexed: 03/17/2024]
Abstract
We report on the demonstration of a diode-pumped, Tm:YLF-based, chirped pulse amplification laser system operating at λ ≈ 1.9 µm that produces amplified pulse energies exceeding 1.5 J using a single 8-pass power amplifier. The amplified pulses are subsequently compressed to sub-300 fs durations by a diffraction grating pair, producing record >1 TW peak power pulses. To the best of our knowledge, this is the highest peak power demonstrated for any solid-state, near-2 µm laser architecture and illustrates the potential of Tm:YLF for the next generation of high-power, diode-pumped ultrashort lasers.
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Morova Y, Ardalı E, Denker B, Galagan B, Sverchkov S, Sennaroglu A. Broadly tunable continuous wave 2.3-µm Tm 3+:tellurite bulk glass laser. OPTICS LETTERS 2023; 48:4681-4684. [PMID: 37656585 DOI: 10.1364/ol.498797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 08/14/2023] [Indexed: 09/03/2023]
Abstract
We report, for the first time to the best of our knowledge, a continuous wave trivalent thulium ion (Tm3+)-doped bulk glass near 2.3 µm. In the experiments, a bulk Tm3+-doped tellurite glass with the stoichiometric composition of 74TeO2-12ZnO-4La2O3-10Na2O (Tm3+:TZLN) was used. Lasing operation was achieved by using an x-fold cavity at the free-running wavelength of 2303 nm. The maximum slope efficiency of 6.2% was obtained with respect to the absorbed pump power with a 1% transmitting output coupler. In this case, as high as 100-mW output power was generated with 2.2 W of absorbed pump power. Continuous, broad tuning was achieved from 2233 nm to 2400 nm. The excitation spectrum of the laser was also investigated and 2.3-µm lasing was obtained by varying the pump wavelength over the 773-809-nm range. The absorption cross section was determined to be 4.4 × 10-21 cm2, based on open-aperture z-scan measurement. By using the laser efficiency data, the emission cross section of the Tm3+:TZLN glass was further determined to be 1.3 × 10-20 cm2 at 2.3 µm.
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Dupont H, Loiko P, Tyazhev A, Giordano L, Pan Z, Chu H, Li D, Viana B, Hideur A, Guillemot L, Braud A, Camy P, Georges P, Druon F. Tm:CALGO lasers at 2.32 µm: cascade lasing and upconversion pumping. OPTICS EXPRESS 2023; 31:18751-18764. [PMID: 37381308 DOI: 10.1364/oe.487590] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 04/07/2023] [Indexed: 06/30/2023]
Abstract
We report on the first laser operation of a disordered Tm:CaGdAlO4 crystal on the 3H4 → 3H5 transition. Under direct pumping at 0.79 µm, it generates 264 mW at 2.32 µm with a slope efficiency of 13.9% and 22.5% vs. incident and absorbed pump power, respectively, and a linear polarization (σ). Two strategies to overcome the bottleneck effect of the metastable 3F4 Tm3+ state leading to the ground-state bleaching are exploited: cascade lasing on the 3H4 → 3H5 and 3F4 → 3H6 transitions and dual-wavelength pumping at 0.79 and 1.05 µm combining the direct and upconversion pumping schemes. The cascade Tm-laser generates a maximum output power of 585 mW at 1.77 µm (3F4 → 3H6) and 2.32 µm (3H4 → 3H5) with a higher slope efficiency of 28.3% and a lower laser threshold of 1.43 W, out of which 332 mW are achieved at 2.32 µm. Under dual-wavelength pumping, further power scaling to 357 mW at at 2.32 µm is observed at the expense of increased laser threshold. To support the upconversion pumping experiment, excited-state absorption spectra of Tm3+ ions for the 3F4 → 3F2,3 and 3F4 → 3H4 transitions are measured for polarized light. Tm3+ ions in CaGdAlO4 exhibit broadband emission at 2.3 - 2.5 µm making this crystal promising for ultrashort pulse generation.
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Tyazhev A, Loiko P, Guillemot L, Kouta A, Solé RM, Mateos X, Aguiló M, Díaz F, Dupont H, Georges P, Druon F, Braud A, Camy P, Hideur A. Excited-state absorption and upconversion pumping of Tm 3+-doped potassium lutetium double tungstate. OPTICS EXPRESS 2023; 31:14808-14820. [PMID: 37157337 DOI: 10.1364/oe.487130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We report on a bulk thulium laser operating on the 3H4 → 3H5 transition with pure upconversion pumping at 1064 nm by an ytterbium fiber laser (addressing the 3F4 → 3F2,3 excited-state absorption (ESA) transition of Tm3+ ions) generating 433 mW at 2291 nm with a slope efficiency of 7.4% / 33.2% vs. the incident / absorbed pump power, respectively, and linear laser polarization representing the highest output power ever extracted from any bulk 2.3 µm thulium laser with upconversion pumping. As a gain material, a Tm3+-doped potassium lutetium double tungstate crystal is employed. The polarized ESA spectra of this material in the near-infrared are measured by the pump-probe method. The possible benefits of dual-wavelength pumping at 0.79 and 1.06 µm are also explored, indicating a positive effect of co-pumping at 0.79 µm on reducing the threshold pump power for upconversion pumping.
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Yu X, Pan Z, Chu H, Zha F, Pan H, Ma L, Loiko P, Camy P, Li D. Cascade lasing at ∼2 μm and ∼2.3 μm in a diode-pumped Tm:YVO 4 laser. OPTICS EXPRESS 2023; 31:13576-13584. [PMID: 37157242 DOI: 10.1364/oe.484647] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We report on the cascade continuous-wave operation of a diode-pumped Tm:YVO4 laser on the 3F4 → 3H6 (at ∼2 μm) and 3H4 → 3H5 (at ∼2.3 μm) Tm3+ transitions. Pumped with a fiber-coupled spatially multimode 794 nm AlGaAs laser diode, the 1.5 at.% Tm:YVO4 laser yielded a maximum total output power of 6.09 W with a slope efficiency of 35.7% out of which the 3H4 → 3H5 laser emission corresponded to 1.15 W at 2291-2295 and 2362-2371 nm with a slope efficiency of 7.9% and a laser threshold of 6.25 W.
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Demirbas U, Thesinga J, Beyatli E, Kellert M, Pergament M, Kärtner FX. Continuous-wave Tm:YLF laser with ultrabroad tuning (1772-2145 nm). OPTICS EXPRESS 2022; 30:41219-41239. [PMID: 36366605 DOI: 10.1364/oe.471288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
We report detailed experimental data aiming for rigorous investigation of Tm:YLF laser performance, especially with a focus on tuning behavior. Continuous-wave (cw) lasing performance of Tm:YLF crystals with thulium dopings in the 2-6% range is investigated under diode and Ti:Sapphire pumping at 792 nm and 780 nm, respectively. While employing the c-axis, we have achieved cw lasing thresholds below 20 mW, laser output power up to 1.42 W, and laser slope efficiencies as high as 70% with respect to absorbed pump power. The passive loss of the Tm:YLF crystal is estimated to be as low as 0.05% per cm, corresponding to a crystal figure of merit above 10000. Via employing this low-loss crystal and a 2-mm thick off-surface optical axis birefringent filter (BRF) with strong sideband rejection, a record cw tuning range covering the 1772-2145 nm interval is demonstrated (except a small gap between 1801-1815nm region). Detailed lifetime and emission cross section measurements have been performed to explain the observed performance, and strategies for further performance enhancement are discussed.
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Dupont H, Guillemot L, Loiko P, Braud A, Doualan JL, Camy P, Georges P, Druon F. Dual-wavelength-pumping of mid-infrared Tm:YLF laser at 2.3 µm: demonstration of pump seeding and recycling processes. OPTICS EXPRESS 2022; 30:32141-32150. [PMID: 36242282 DOI: 10.1364/oe.468695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 07/20/2022] [Indexed: 06/16/2023]
Abstract
Upconversion pumping of thulium lasers emitting around 2.3 µm (the 3H4 → 3H5 transition) has recently attracted a lot of attention as it is compatible with the mature Yb-laser technology. To explore this possibility, we built a mid-infrared Tm:LiYF4 laser pumped by an Yb:CaF2 laser at 1.05 µm delivering an output power of 110 mW at 2.31 µm for a maximum incident pump power of 2.0 W. A strong absorption issue appeared in the Tm laser: the slope efficiency vs. the incident pump power was 7.6% while that vs. the absorbed pump power reached 29%. To overcome this issue, a dual-wavelength pumping at 0.78 µm and 1.05 µm was explored (combining both the direct and upconversion pumping schemes). The reciprocal interplay between the two pumps was studied to evaluate their benefits in terms of the pump absorption and laser efficiency. We observed an interesting decrease of the laser threshold for upconversion pumping when adding a small fraction of the direct pump revealing a seeding effect for the excited-state absorption from the metastable 3F4 level. A recycling process of this manifold by excited-state absorption in the 3F4 → 3F2,3 loop was also observed. The pump absorption seeding is a viable route for the development of low-threshold upconversion pumped thulium lasers.
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Pirri A, Maksimov RN, Li J, Vannini M, Toci G. Achievements and Future Perspectives of the Trivalent Thulium-Ion-Doped Mixed-Sesquioxide Ceramics for Laser Applications. MATERIALS (BASEL, SWITZERLAND) 2022; 15:2084. [PMID: 35329536 PMCID: PMC8950303 DOI: 10.3390/ma15062084] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/05/2022] [Accepted: 03/07/2022] [Indexed: 02/04/2023]
Abstract
This paper is devoted to reviewing the latest results achieved in solid-state lasers based on thulium-doped mixed-sesquioxide ceramics, i.e., (Lu,Sc,Y)2O3. The near- and mid-infrared regions are of interest for many applications, from medicine to remote sensing, as they match molecular fingerprints and cover several atmospheric transparency windows. These matrices are characterized by a strong electron-phonon interaction-which results in a large splitting of the ground state-and by a spectral broadening of the optical transition suitable for developing tunable and short-pulse lasers. In particular, the manuscript reports on the trivalent thulium laser transitions at 1.5, 1.9, and 2.3 µm, along with the thermal and optical characteristics of the (Lu,Sc,Y)2O3 ceramics, including the fabrication techniques, spectroscopic and optical properties, and laser performances achieved in different pumping regimes, such as continuous-wave (CW), quasi-CW, and pulsed modes. A comparison of the performance obtained with these mixed-sesquioxide ceramics and with the corresponding crystals is reported.
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Affiliation(s)
- Angela Pirri
- Istituto di Fisica Applicata “N. Carrara”, Consiglio Nazionale delle Ricerche, 50019 Sesto Fiorentino, FI, Italy
| | - Roman N. Maksimov
- Institute of Electrophysics UrB RAS, 620016 Ekaterinburg, Russia;
- Ural Federal University Named after the First President of Russia B.N. Yeltsin, 620002 Ekaterinburg, Russia
| | - Jiang Li
- Key Laboratory of Transparent Opto-Functional Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China;
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Matteo Vannini
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, INO-CNR, 50019 Sesto Fiorentino, FI, Italy; (M.V.); (G.T.)
| | - Guido Toci
- Istituto Nazionale di Ottica, Consiglio Nazionale delle Ricerche, INO-CNR, 50019 Sesto Fiorentino, FI, Italy; (M.V.); (G.T.)
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Chen H, Zhang Z, Wang G, Shang Z, Li J, Zhao Z, Zhang M, Guo K, Yang J, Yan P. Nonlinear optical response of inverse-designed integrated photonic devices. OPTICS LETTERS 2022; 47:1254-1257. [PMID: 35230340 DOI: 10.1364/ol.453299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Gradient-based optimization combined with the adjoint method has been demonstrated to be an efficient way to design a nano-structure with a vast number of degrees of freedom. However, most inverse-designed photonic devices are applied as linear photonic devices. Here, we demonstrate the nonlinear optical response in inverse-designed integrated splitters fabricated on a SiN platform. The splitting ratio is tunable under different incident powers. The thermo-optical effect can be used as an effective approach for adjusting the nonlinear optical response threshold and modulation depth of the device. These promising results indicate the great potential of inverse-designed photonic devices in nonlinear optics and optical communications.
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Zhao Y, Wang L, Chen W, Loiko P, Wang Y, Pan Z, Yang H, Jing W, Huang H, Liu J, Mateos X, Wang Z, Xu X, Griebner U, Petrov V. Kerr-lens mode-locked Tm-doped sesquioxide ceramic laser. OPTICS LETTERS 2021; 46:3428-3431. [PMID: 34264230 DOI: 10.1364/ol.431067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/13/2021] [Indexed: 06/13/2023]
Abstract
Kerr-lens mode-locked solid-state laser operation at ∼2µm is investigated. Using a Tm3+-doped (Lu,Sc)2O3 "mixed" sesquioxide ceramic as a gain medium, pulses as short as 58 fs are generated at ∼2081nm via soft-aperture Kerr-lens mode locking. The average output power amounts to 220 mW at a pulse repetition rate of 84.8 MHz. The emitted spectrum at the long-wavelength wing extends to >2.2µm which is attributed to vibronic transitions of the Tm3+ ions. The latter is found to be essential for generating pulses with durations in the 50 fs range.
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Tyazhev A, Starecki F, Cozic S, Loiko P, Guillemot L, Braud A, Joulain F, Tang M, Godin T, Hideur A, Camy P. Watt-level efficient 2.3 µm thulium fluoride fiber laser. OPTICS LETTERS 2020; 45:5788-5791. [PMID: 33057285 DOI: 10.1364/ol.403450] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
We report on an efficient mid-infrared thulium (Tm) fiber laser operating on the 3H4→3H5 transition and featuring an upconversion pumping scheme. This laser comprises a heavily Tm3+-doped (2.50 mol. %) zirconium fluoride glass fiber pumped by a tunable Yb fiber laser around 1.05 µm corresponding to the 3F4→3F2,3 excited-state absorption transition. The laser generates 1.24 W at 2269-2282 nm with a slope efficiency of 37% in the quasi-continuous-wave regime. The Tm-glass fiber exhibits a broadband 3H4→3H5 emission with a bandwidth of 173 nm, making it very promising for femtosecond fiber oscillators at ∼2.3µm.
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Kifle E, Loiko P, Guillemot L, Doualan JL, Starecki F, Braud A, Georges T, Rouvillain J, Camy P. Watt-level diode-pumped thulium lasers around 2.3 µm. APPLIED OPTICS 2020; 59:7530-7539. [PMID: 32902451 DOI: 10.1364/ao.400632] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/21/2020] [Indexed: 06/11/2023]
Abstract
We report on efficient diode-pumped mid-infrared lasers based on Tm:LiYF4, Tm:Y3Al5O12, and Tm:YAlO3 crystals. These lasers operate in the continuous-wave (CW) regime and deliver watt-level output power at the wavelengths of 2.2-2.3 µm (the 3H4→3H5Tm3+ transition). In particular, a 1.8 at. % Tm:YAlO3 laser pumped at 789 nm generates a maximum CW output power of 1.32 W at 2272-2277 nm with a slope efficiency of 33.1% (with respect to the absorbed pump power), a linear laser polarization (E∥b), and a fundamental transverse output mode (the measured Mx2=1.26, My2=1.68). In the quasi-CW regime, the output peak power is scaled up to 2.69 W. The pump quantum efficiency and the fractional heat loading are estimated and discussed.
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Muti A, Baylam I, Tonelli M, Sennaroglu A. Tunable continuous-wave laser operation of Tm 3+:BaY 2F 8 near 2.3 µm. OPTICS LETTERS 2020; 45:4104-4107. [PMID: 32735234 DOI: 10.1364/ol.394261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
We report, for the first time to our knowledge, tunable continuous-wave laser action in the Tm3+:BaY2F8 (BYF) crystal near 2.3 µm. In the experiments, a BYF crystal doped with 3 at. % thulium was end pumped with a narrow-linewidth, tunable Ti3+:sapphire laser with up to 920 mW of incident power. Lasing was achieved for the two pump polarizations of E//x and E//y. The best power performance was obtained in the case of E//x, double-end pumping, where 100 mW of output power was obtained at 2290 nm with 920 mW of pump power and 1% output coupler. The laser could be continuously tuned from 2233 to 2385 nm. Excitation spectra for E//x and E//y pumping were measured in the 760-810 nm range, and the optimum pumping wavelength was determined to be 779 nm for E//x. By using the lifetime and lasing threshold data, the stimulated emission cross section at 2290 nm was further determined to be (0.66±0.06)×10-24m2.
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Morova Y, Tonelli M, Petrov V, Sennaroglu A. Upconversion pumping of a 2.3 µm Tm 3+:KY 3F 10 laser with a 1064 nm ytterbium fiber laser. OPTICS LETTERS 2020; 45:931-934. [PMID: 32058509 DOI: 10.1364/ol.384284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/09/2020] [Indexed: 06/10/2023]
Abstract
We report efficient lasing of the isotropic ${{\rm Tm}^{3 + }}\!:\!{{\rm KY}_3}{{\rm F}_{10}}$Tm3+:KY3F10 crystal near 2.3 µm via upconversion pumping with a 1064 nm ytterbium fiber laser as the pump source. When pumped at 1064 nm, an x-cavity ${{\rm Tm}^{3 + }}\!:\!{{\rm KY}_3}{{\rm F}_{10}}$Tm3+:KY3F10 laser operated at the free-running wavelength of 2344 nm. Lasing was obtained with output couplers having transmissions in the range of 1-3%, and as high as 124 mW of continuous-wave (cw) output power was generated with 604 mW of absorbed pump power by using the 3% output coupler. Broadly tunable cw lasing could be obtained in the 2268-2373 nm wavelength range. An analysis of the experimental power efficiency data shows that nearly all of the absorbed pump photons were converted to 2.3 µm laser output after accounting for the quantum defect of the laser transition and resonator losses. We expect that higher lasing efficiency should be possible by using longer crystals to increase the pump absorption.
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Guillemot L, Loiko P, Soulard R, Braud A, Doualan JL, Hideur A, Camy P. Close look on cubic Tm:KY 3F 10 crystal for highly efficient lasing on the 3H 4 → 3H 5 transition. OPTICS EXPRESS 2020; 28:3451-3463. [PMID: 32122013 DOI: 10.1364/oe.382650] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 12/19/2019] [Indexed: 06/10/2023]
Abstract
We report on Czochralski growth, detailed ground- and excited-state absorption and emission spectroscopy and highly-efficient mid-infrared (∼2.3 µm) laser operation of a cubic potassium yttrium fluoride crystal, Tm:KY3F10. The peak stimulated-emission cross-section for the 3H4 → 3H5 transition is 0.34×10-20 cm2 at 2345 nm with an emission bandwidth exceeding 50 nm. The excited-state absorption spectra for the 3F4 → 3F2,3 and 3F4 → 3H4 transitions are measured and the cross-relaxation is quantified. A continuous-wave 5 at.% Tm:KY3F10 laser generated 0.84 W at 2331-2346 nm by pumping at 773 nm, with a record-high slope efficiency of 47.7% (versus the incident pump power) owing to the efficient action of energy-transfer upconversion leading to a pump quantum efficiency approaching 2. The first Tm:KY3F10 laser with ESA-assisted upconversion pumping (at 1048 nm) is also demonstrated. Due to its broadband emission properties, Tm:KY3F10 is promising for ultrashort pulse generation at ∼2.3-2.4 µm.
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Muti A, Canbaz F, Tonelli M, Eun Bae J, Rotermund F, Petrov V, Sennaroglu A. Graphene mode-locked operation of Tm 3+:YLiF 4 and Tm 3+:KY 3F 10 lasers near 2.3 µm. OPTICS LETTERS 2020; 45:656-659. [PMID: 32004276 DOI: 10.1364/ol.385629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/03/2020] [Indexed: 06/10/2023]
Abstract
We report experimental demonstration of graphene mode-locked operation of ${{\rm Tm}^{3 + }}\!:\!{{\rm YLiF}_4}$Tm3+:YLiF4 (YLF) and ${{\rm Tm}^{3 + }}\!:\!{{\rm KY}_3}{{\rm F}_{10}}$Tm3+:KY3F10 (KYF) lasers near 2.3 µm. To scale up the intracavity pulse energy, the cavity was extended, and double-end pumping was employed with a continuous-wave, tunable ${{\rm Ti}^{3 + }}\!:\!{\rm sapphire}$Ti3+:sapphire laser delivering up to 1 W near 780 nm. The extended ${{\rm Tm}^{3 + }}\!:\!{\rm KYF}$Tm3+:KYF laser cavity was purged with dry nitrogen to eliminate pulsing instabilities due to atmospheric absorption lines, but this was not needed in the case of the ${{\rm Tm}^{3 + }}\!:\!{\rm YLF}$Tm3+:YLF laser. Once initiated by graphene, stable uninterrupted mode-locked operation could be maintained with both lasers. With the extended cavity ${{\rm Tm}^{3 + }}\!:\!{\rm YLF}$Tm3+:YLF laser, 921 fs pulses were generated at a repetition rate of 17.2 MHz at 2304 nm. 739 fs pulses were obtained at the repetition rate of 54 MHz from the ${{\rm Tm}^{3 + }}\!:\!{\rm KYF}$Tm3+:KYF laser at 2340 nm. The corresponding pulse energy and peak power were 2.4 nJ and 2.6 kW for the ${{\rm Tm}^{3 + }}\!:\!{\rm YLF}$Tm3+:YLF laser, and 1.2 nJ and 1.6 kW for the ${{\rm Tm}^{3 + }}\!:\!{\rm KYF}$Tm3+:KYF laser. We foresee that it should be possible to generate shorter pulses at higher pump levels.
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Huang H, Wang S, Chen H, Antipov OL, Balabanov SS, Shen D. High power simultaneous dual-wavelength CW and passively-Q-switched laser operation of LD pumped Tm:YLF at 1.9 and 2.3 µm. OPTICS EXPRESS 2019; 27:38593-38601. [PMID: 31878623 DOI: 10.1364/oe.381821] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
Simultaneous dual-wavelength laser oscillation of Tm:YLF at 1.9 and 2.3 µm were successfully realized. The three-mirror cavity was exploited to study dual-wavelength laser performance, which is formed by a shared input mirror and two independent output couplers for the two laser wavelengths. Under an absorbed pump power of 15.2 W, the maximum CW output powers of 5.49 W around 1908nm and 1.12 W around 2305 nm were simultaneously obtained, corresponding to a total optical-to-optical conversion efficiency of 43.5%. A Cr2+:ZnSe was further used to passively Q-switch the dual-wavelength laser, generating pulses with pulse widths of 554 ns at 1.9 µm and 4 µs at 2.3 µm. To the best of our knowledge, this is the first report on the dual-wavelength laser operation of Tm3+-single-doped solid-state laser at 1.9 and 2.3 µm. The higher optical conversion efficiency, smaller wavelength competition effect and simultaneous dual-wavelength output make this Tm-doped solid-state laser have potential application in medical surgery.
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Na Q, Huang Z, He M, Chen Z, Xu T, Wang L, Yan P, Li Y, Luo S, Xu C, Fan D. Watt-level passively mode-locked Tm:YLF laser at 1.83 µm. OPTICS EXPRESS 2019; 27:35230-35237. [PMID: 31878695 DOI: 10.1364/oe.27.035230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 11/06/2019] [Indexed: 06/10/2023]
Abstract
Passive, continuous-wave mode-locked (CWML) operation of a 1.83 µm Tm:YLF laser is experimentally demonstrated for the first time, to the best of our knowledge. Two specially selected output couplers are used to realize this operation. Stability of the CWML laser is obtained with a commercial semiconductor saturable absorber mirror. The maximum average output power is 1.04 W with a pulse duration of 107 ps and repetition rate of 54.1 MHz. Further, a 0.1 mm fused-quartz Fabry-Perot etalon is used to tune the central wavelength of the stable CWML laser at 1827.2 nm, 1829.5 nm, 1831.9 nm, and 1833.5 nm.
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Guillemot L, Loiko P, Braud A, Doualan JL, Hideur A, Koselja M, Moncorge R, Camy P. Continuous-wave Tm:YAlO 3 laser at ∼2.3 μm. OPTICS LETTERS 2019; 44:5077-5080. [PMID: 31613268 DOI: 10.1364/ol.44.005077] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
The orthorhombic Tm3+:YAlO3 crystal is promising for laser operation at the H43→F43 (1.5 μm) and H43→H53 (2.3 μm) transitions. Stimulated-emission cross-sections for these transitions are determined with polarized light. Peak values of 0.59×10-20 cm2 and 0.80×10-20 cm2 are found at 1438 nm and 2275 nm, respectively, both for E∥b. The cross-relaxation defining the upper-laser level lifetime is quantified. Continuous-wave lasing at the H43→H53 transition is achieved with an a-cut 1.5 at.% Tm:YAlO3 crystal. The laser generated 254 mW at 2273 nm with a slope efficiency of 17.8% and linear polarization (E∥b).
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Guillemot L, Loiko P, Soulard R, Braud A, Doualan JL, Hideur A, Moncorgé R, Camy P. Thulium laser at ∼2.3 μm based on upconversion pumping. OPTICS LETTERS 2019; 44:4071-4074. [PMID: 31415549 DOI: 10.1364/ol.44.004071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/01/2019] [Indexed: 06/10/2023]
Abstract
We report on novel upconversion (UC) pumping schemes for 2.3 μm thulium (Tm) lasers (the H43→H53 transition) based on a photon avalanche mechanism populating the intermediate metastable level (F43) acting as an effective ground state. The proposed pump wavelengths are ∼1 and ∼1.5 μm, each one corresponding to a resonant excited-state absorption transition F43→F2,33 and F43→H43, respectively. UC pumping at 1040, 1055, and 1451 nm of 2.3 μm Tm:LiYF4 lasers is demonstrated. In the former case, the laser generates 102 mW at 2302 nm with a slope efficiency of 14.6% (versus the incident pump power). The laser dynamics is studied. UC pumping is promising for reaching high efficiencies in 2.3 μm Tm lasers.
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Muti A, Tonelli M, Petrov V, Sennaroglu A. Continuous-wave mid-infrared laser operation of Tm 3+:KY 3F 10 at 2.3 μm. OPTICS LETTERS 2019; 44:3242-3245. [PMID: 31259931 DOI: 10.1364/ol.44.003242] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 05/22/2019] [Indexed: 06/09/2023]
Abstract
We report continuous-wave lasing demonstration of a Tm3+:KY3F10 crystalline gain medium at 2343 nm. A narrow-linewidth, tunable, continuous-wave Ti3+:sapphire laser was used to end pump a Tm3+:KY3F10 crystal with thulium doping of 8 at. %. With 1 W of pump power, the resonator with a 1% output coupler generated output powers of 31 and 122 mW in single-pumping and double-pumping configurations, respectively. Excitation efficiency of the laser was investigated for pump wavelengths in the 765-806 nm range. Four pump bands were identified in this wavelength range, with the two most efficient pump bands centered at 773 and 778 nm. The output of the laser could be tuned smoothly and continuously over a spectral width of 125 nm from 2260 to 2385 nm. The lifetime of the H43 level was further measured to be 16 μs, and the emission cross section was determined based on lasing threshold measurements.
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Beyatli E, Sumpf B, Erbert G, Demirbas U. Efficient Tm:YAG and Tm:LuAG lasers pumped by 681 nm tapered diodes. APPLIED OPTICS 2019; 58:2973-2980. [PMID: 31044902 DOI: 10.1364/ao.58.002973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
In this paper, we present highly efficient continuous-wave (cw) laser operation of Tm:YAG and Tm:LuAG lasers pumped by high-brightness red tapered diodes. The single-emitter tapered diode lasers (TDLs) provide up to 1 W of pump power around 680 nm. By adjusting the operation temperature of the TDL, the pump central wavelength could be matched to the strong absorption peak of Tm3+ ions in this region (H63→F33 excitation). This absorption peak is around threefold stronger than the usually employed 785 nm transition (H63→H34). In the cw laser experiments, we have achieved slope efficiencies exceeding 55% at room temperature, which is far above the Stokes limited slope efficiency (34%), indicating presence of a strong two-for-one cross-relaxation process. Pumping with high-brightness tapered diode lasers further facilitated usage of smaller pump spots (enabling quite low lasing thresholds) and generation of near-diffraction limited output beam profiles from standard z-type cavities. To the best of our knowledge, this is the first report of diode pumping of Tm-doped solid-state lasers around 680 nm as well as the first usage of TDLs as pump sources in Tm-doped laser systems.
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Pan Z, Wang Y, Zhao Y, Kowalczyk M, Sotor J, Yuan H, Zhang Y, Dai X, Cai H, Bae JE, Choi SY, Rotermund F, Loiko P, Serres JM, Mateos X, Griebner U, Petrov V. Sub-80 fs mode-locked Tm,Ho-codoped disordered garnet crystal oscillator operating at 2081 nm. OPTICS LETTERS 2018; 43:5154-5157. [PMID: 30320843 DOI: 10.1364/ol.43.005154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 09/18/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate a mode-locked (ML) femtosecond laser based on the disordered garnet crystal Tm,Ho:CNGG. Employing a single-walled carbon nanotube saturable absorber, pulses as short as 83 and 76 fs at 2081 nm are achieved without and with external compression, respectively. The latter represents, to the best of our knowledge, the shortest pulse duration obtained from any Ho-doped or Tm,Ho-codoped laser. The average power amounts to 67 mW at a repetition rate of 102 MHz. By analyzing the soliton ML regime, the nonlinear refractive index of Tm,Ho:CNGG is estimated to be ∼1.1×10-19 m2/W.
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