1
|
Bu L, Chen S, Baronio F, Trillo S. Resonant radiation emitted by solitary waves via cascading in quadratic media. OPTICS EXPRESS 2023; 31:8307-8324. [PMID: 36859946 DOI: 10.1364/oe.481676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/05/2023] [Indexed: 06/18/2023]
Abstract
We present a systematic investigation of the resonant radiation emitted by localized soliton-like wave-packets supported by second-harmonic generation in the cascading regime. We emphasize a general mechanism which allows for the resonant radiation to grow without the need for higher-order dispersion, primarily driven by the second-harmonic component, while radiation is also shed around the fundamental-frequency component through parametric down-conversion processes. The ubiquity of such a mechanism is revealed with reference to different localized waves such as bright solitons (both fundamental and second-order), Akhmediev breathers, and dark solitons. A simple phase matching condition is put forward to account for the frequencies radiated around such solitons, which agrees well with numerical simulations performed against changes of material parameters (say, phase mismatch, dispersion ratio). The results provide explicit understanding of the mechanism of soliton radiation in quadratic nonlinear media.
Collapse
|
2
|
Bu L, Baronio F, Chen S, Trillo S. Quadratic Peregrine solitons resonantly radiating without higher-order dispersion. OPTICS LETTERS 2022; 47:2370-2373. [PMID: 35561353 DOI: 10.1364/ol.456187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/10/2022] [Indexed: 06/15/2023]
Abstract
We show that two-color Peregrine solitary waves in quadratic nonlinear media can resonantly radiate dispersive waves even in the absence of higher-order dispersion, owing to a phase-matching mechanism that involves the weaker second-harmonic component. We give very simple criteria for calculating the radiated frequencies in terms of material parameters, finding excellent agreement with numerical simulations.
Collapse
|
3
|
Castelló-Lurbe D. Breaking fundamental noise limitations to supercontinuum generation. OPTICS LETTERS 2022; 47:1299-1302. [PMID: 35290298 DOI: 10.1364/ol.452104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
Supercontinuum generation in the anomalous group-velocity dispersion regime is widely considered to be inherently unstable against input pulse fluctuations. This constraint has compelled a coherent supercontinuum to be triggered by femtosecond pulses. In this work, conditions for breaking this fundamental limitation are analytically derived and realized in a silicon waveguide by exploiting the Kerr nonlinearity dispersion. On this basis, coherent supercontinuum generation with picosecond pulses and anomalous group-velocity dispersion is numerically demonstrated, which crosses a long-standing frontier in nonlinear optics.
Collapse
|
4
|
Ji X, Mojahed D, Okawachi Y, Gaeta AL, Hendon CP, Lipson M. Millimeter-scale chip-based supercontinuum generation for optical coherence tomography. SCIENCE ADVANCES 2021; 7:eabg8869. [PMID: 34533990 PMCID: PMC8448444 DOI: 10.1126/sciadv.abg8869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Supercontinuum sources for optical coherence tomography (OCT) have raised great interest as they provide broad bandwidth to enable high resolution and high power to improve imaging sensitivity. Commercial fiber-based supercontinuum systems require high pump powers to generate broad bandwidth and customized optical filters to shape/attenuate the spectra. They also have limited sensitivity and depth performance. We introduce a supercontinuum platform based on a 1-mm2 Si3N4 photonic chip for OCT. We directly pump and efficiently generate supercontinuum near 1300 nm without any postfiltering. With a 25-pJ pump pulse, we generate a broadband spectrum with a flat 3-dB bandwidth of 105 nm. Integrating the chip into a spectral domain OCT system, we achieve 105-dB sensitivity and 1.81-mm 6-dB sensitivity roll-off with 300-μW optical power on sample. We image breast tissue to demonstrate strong imaging performance. Our chip will pave the way toward portable OCT and incorporating integrated photonics into optical imaging technologies.
Collapse
Affiliation(s)
- Xingchen Ji
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
| | - Diana Mojahed
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Yoshitomo Okawachi
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
| | - Alexander L. Gaeta
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA
| | - Christine P. Hendon
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Corresponding author. (M.L.); (C.P.H.)
| | - Michal Lipson
- Department of Electrical Engineering, Columbia University, New York, NY 10027, USA
- Corresponding author. (M.L.); (C.P.H.)
| |
Collapse
|
5
|
Castelló-Lurbe D. Dispersive-wave self-frequency shift unveiled through length scales propagation. OPTICS LETTERS 2021; 46:4152-4155. [PMID: 34469962 DOI: 10.1364/ol.434304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
Nonlinear propagation of light pulses can excite dispersive waves anchored at frequencies determined by the chromatic dispersion curve. In this work, conditions enabling dispersive-wave self-frequency shift over the propagation distance are analytically derived in the normal dispersion regime. Importantly, this novel, to the best of our knowledge, scenario is not found by solving the complex dynamics of the pulse, but by studying the evolution of the nonlinear and dispersive length scales. This approach allows a simpler, yet consistent and insightful, analysis that may also be very useful in other nonlinear regimes.
Collapse
|
6
|
Lamee KF, Carlson DR, Newman ZL, Yu SP, Papp SB. Nanophotonic tantala waveguides for supercontinuum generation pumped at 1560 nm. OPTICS LETTERS 2020; 45:4192-4195. [PMID: 32735256 DOI: 10.1364/ol.396950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
We experimentally demonstrate efficient and broadband supercontinuum generation in nonlinear tantala (Ta2O5) waveguides using a 1560 nm femtosecond seed laser. With incident pulse energies as low as 100 pJ, we create spectra spanning up to 1.6 octaves across the visible and infrared. Fabricated devices feature propagation losses as low as 10 dB/m, and they can be dispersion engineered through lithographic patterning for specific applications. We show a waveguide design suitable for low-power self-referencing of a fiber frequency comb that produces dispersive-wave radiation directly at the second-harmonic wavelength of the seed laser. A fiber-connectorized, hermetically sealed module with 2 dB per facet insertion loss and watt-level average-power handling is also described. Highly efficient and fully packaged tantala waveguides may open new possibilities for the integration of nonlinear nanophotonics into systems for precision timing, quantum science, biological imaging, and remote sensing.
Collapse
|
7
|
Shams-Ansari A, Latawiec P, Okawachi Y, Venkataraman V, Yu M, Desiatov B, Atikian H, Harris GL, Picqué N, Gaeta AL, Lončar M. Supercontinuum generation in angle-etched diamond waveguides. OPTICS LETTERS 2019; 44:4056-4059. [PMID: 31415546 DOI: 10.1364/ol.44.004056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
We experimentally demonstrate on-chip supercontinuum generation in the visible region in angle-etched diamond waveguides. We measure an output spectrum spanning 670-920 nm in a 5-mm-long waveguide using 100-fs pulses with 187 pJ of incident pulse energy. Our fabrication technique, combined with diamond's broad transparency window, offers a potential route toward broadband supercontinuum generation in the UV domain.
Collapse
|
8
|
Gonzalez GFC, Malinowski M, Honardoost A, Fathpour S. Design of a hybrid chalcogenide-glass on lithium-niobate waveguide structure for high-performance cascaded third- and second-order optical nonlinearities. APPLIED OPTICS 2019; 58:D1-D6. [PMID: 31044813 DOI: 10.1364/ao.58.0000d1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 01/04/2019] [Indexed: 06/09/2023]
Abstract
Dispersion engineering for efficient supercontinuum generation (SCG) is investigated in a hybrid nonlinear photonic platform that allows cascaded third- and second-order optical nonlinearities in transverse-electric (TE) guided modes. The highly nonlinear chalcogenide waveguides enable SCG spanning over 1.25 octaves (from about 1160 nm to more than 2800 nm at 20 dB below maximum power), while the TE polarization attained is compatible with efficient second-harmonic generation in a subsequent thin-film lithium niobate waveguide integrated monolithically on the same chip. A low-energy pump pulsed laser source of only 25 pJ with 250 fs duration, centered at a wavelength of 1550 nm, can achieve such wideband SCG. The design presented is suitable for the f-to-2f carrier-envelope offset detection technique of stabilized optical frequency comb sources.
Collapse
|
9
|
Yu M, Desiatov B, Okawachi Y, Gaeta AL, Lončar M. Coherent two-octave-spanning supercontinuum generation in lithium-niobate waveguides. OPTICS LETTERS 2019; 44:1222-1225. [PMID: 30821753 DOI: 10.1364/ol.44.001222] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/24/2019] [Indexed: 05/27/2023]
Abstract
We demonstrate coherent supercontinuum generation (SCG) in a monolithically integrated lithium-niobate waveguide, under the presence of second- and third-order nonlinear effects. We achieve more than two octaves of optical bandwidth in a 0.5-cm-long waveguide with 100-picojoule-level pulses. Dispersion engineering of the waveguide allows for spectral overlap between the SCG and the second harmonic, which enables direct detection of the carrier-envelope offset frequency fCEO using a single waveguide. We measure the fCEO of our femtosecond pump source with a 30-dB signal-to-noise ratio.
Collapse
|
10
|
Okawachi Y, Yu M, Cardenas J, Ji X, Klenner A, Lipson M, Gaeta AL. Carrier envelope offset detection via simultaneous supercontinuum and second-harmonic generation in a silicon nitride waveguide. OPTICS LETTERS 2018; 43:4627-4630. [PMID: 30272699 DOI: 10.1364/ol.43.004627] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 08/22/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate a chip-scale f-2f interferometer for carrier-envelope-offset frequency (fCEO) detection. This is enabled by simultaneously producing octave-spanning coherent supercontinuum generation and second-harmonic generation in a single dispersion-engineered silicon nitride waveguide. We measure the fCEO beatnote of an 80 MHz modelocked pump source with a signal-to-noise ratio of 25 dB. Our simple approach for f-2f interferometry enables a straightforward route towards a chip-scale self-referenced frequency comb source that can operate at low pulse energies.
Collapse
|
11
|
Nguyen HPT, Nagasaka K, Tuan TH, Saini TS, Luo X, Suzuki T, Ohishi Y. Highly coherent supercontinuum in the mid-infrared region with cascaded tellurite and chalcogenide fibers. APPLIED OPTICS 2018; 57:6153-6163. [PMID: 30117996 DOI: 10.1364/ao.57.006153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/26/2018] [Indexed: 06/08/2023]
Abstract
We numerically investigate two-step supercontinuum (SC) generation using cascaded tellurite and chalcogenide fibers with all-normal group velocity dispersion pumped by a femtosecond laser at 2 μm. The optimized tellurite fiber is a hybrid microstructured optical fiber with a core surrounded by 12 rods. It has flat normal chromatic dispersion from 2 to 5 μm. The chalcogenide fiber is a double-core fiber with flat normal chromatic dispersion from 4 to 10 μm. The output SC spectrum from the best candidate fibers spans from 0.78 to 8.3 μm with coherence of unity all over the spectrum. Such high coherence pulse with broad spectrum will be valuable for many applications in tomography, ultrafast transient absorption spectroscopy, etc. The proposed fiber structures are all-solid and are feasible for fabrication with the common rod-in-tube method. This implies that two-step SC is a potential way to obtain broad, highly coherent SC in the mid-infrared.
Collapse
|
12
|
Power and chirp effects on the frequency stability of resonant dispersive waves generated in photonic crystal fibres. Sci Rep 2018; 8:181. [PMID: 29317707 PMCID: PMC5760690 DOI: 10.1038/s41598-017-18544-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/13/2017] [Indexed: 11/12/2022] Open
Abstract
Optimization of laser output parameters vs. f-to-2f beating signals can be mutually contradicting, when an octave-spanning supercontinuum is employed for f-to-2f measurements. We show that resonant dispersive waves will solve this issue, thanks to their frequency stability against changes in laser power and chirping.
Collapse
|