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A mid-infrared lab-on-a-chip for dynamic reaction monitoring. Nat Commun 2022; 13:4753. [PMID: 35963870 PMCID: PMC9376098 DOI: 10.1038/s41467-022-32417-7] [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: 02/14/2022] [Accepted: 07/29/2022] [Indexed: 11/08/2022] Open
Abstract
Mid-infrared spectroscopy is a sensitive and selective technique for probing molecules in the gas or liquid phase. Investigating chemical reactions in bio-medical applications such as drug production is recently gaining particular interest. However, monitoring dynamic processes in liquids is commonly limited to bulky systems and thus requires time-consuming offline analytics. In this work, we show a next-generation, fully-integrated and robust chip-scale sensor for online measurements of molecule dynamics in a liquid solution. Our fingertip-sized device utilizes quantum cascade technology, combining the emitter, sensing section and detector on a single chip. This enables real-time measurements probing only microliter amounts of analyte in an in situ configuration. We demonstrate time-resolved device operation by analyzing temperature-induced conformational changes of the model protein bovine serum albumin in heavy water. Quantitative measurements reveal excellent performance characteristics in terms of sensor linearity, wide coverage of concentrations, extending from 0.075 mg ml-1 to 92 mg ml-1 and a 55-times higher absorbance than state-of-the-art bulky and offline reference systems.
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Corrias N, Gabbrielli T, De Natale P, Consolino L, Cappelli F. Analog FM free-space optical communication based on a mid-infrared quantum cascade laser frequency comb. OPTICS EXPRESS 2022; 30:10217-10228. [PMID: 35472994 DOI: 10.1364/oe.443483] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
Quantum cascade laser frequency combs are nowadays well-appreciated sources for infrared spectroscopy. Here their applicability for free-space optical communication is demonstrated. The spontaneously-generated intermodal beat note of the frequency comb is used as carrier for transferring the analog signal via frequency modulation. Exploiting the atmospheric transparency window at 4 µm, an optical communication with a signal-to-noise ratio up to 65 dB is realized, with a modulation bandwidth of 300 kHz. The system tolerates a maximum optical attenuation exceeding 35 dB. The possibility of parallel transmission of an independent digital signal via amplitude modulation at 5 Mbit/s is also demonstrated.
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Zhou W, Wu D, Lu QY, Slivken S, Razeghi M. Single-mode, high-power, mid-infrared, quantum cascade laser phased arrays. Sci Rep 2018; 8:14866. [PMID: 30291326 PMCID: PMC6173754 DOI: 10.1038/s41598-018-33024-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 09/19/2018] [Indexed: 11/24/2022] Open
Abstract
We demonstrate single-mode, 16-channel, optical phased arrays based on quantum cascade laser technology, with emission wavelengths around 4.8 µm. The integrated device consists of a distributed feedback seed section, a highly-efficient tree array multi-mode interferometer power splitter, and a 16-channel amplifier array with a 4° angled facet termination. With a single layer Y2O3 coating, the angled facet reflectivity is estimated to be less than 0.1% for suppressing amplifier self-lasing. A peak output power of 30 W is achieved with an emission spectrum narrower than 11 nm and a side mode suppression ratio over 25 dB. Far field distribution measurement result indicates a uniform phase distribution across the array output. Using the same phased array architecture, we also demonstrate single-mode 3.8 µm QCL amplifier arrays with up to 20 W output power.
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Affiliation(s)
- Wenjia Zhou
- Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, 60208, USA
| | - Donghai Wu
- Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, 60208, USA
| | - Quan-Yong Lu
- Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, 60208, USA
| | - Steven Slivken
- Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, 60208, USA
| | - Manijeh Razeghi
- Center for Quantum Devices, Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL, 60208, USA.
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Zhu H, Zhu H, Wang F, Chang G, Yu C, Yan Q, Chen J, Li L, Davies AG, Linfield EH, Tang Z, Chen P, Lu W, Xu G, He L. Terahertz master-oscillator power-amplifier quantum cascade laser with a grating coupler of extremely low reflectivity. OPTICS EXPRESS 2018; 26:1942-1953. [PMID: 29401915 DOI: 10.1364/oe.26.001942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/16/2018] [Indexed: 06/07/2023]
Abstract
A terahertz master-oscillation power-amplifier quantum cascade laser (THz-MOPA-QCL) is demonstrated where a grating coupler is employed to efficiently extract the THz radiation. By maximizing the group velocity and eliminating the scattering of THz wave in the grating coupler, the residue reflectivity is reduced down to the order of 10-3. A buried DFB grating and a tapered preamplifier are proposed to improve the seed power and to reduce the gain saturation, respectively. The THz-MOPA-QCL exhibits single-mode emission, a single-lobed beam with a narrow divergence angle of 18° × 16°, and a pulsed output power of 136 mW at 20 K, which is 36 times that of a second-order DFB laser from the same material.
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Figueiredo P, Suttinger M, Go R, Tsvid E, Patel CKN, Lyakh A. Progress in high-power continuous-wave quantum cascade lasers [Invited]. APPLIED OPTICS 2017; 56:H15-H23. [PMID: 29091662 DOI: 10.1364/ao.56.000h15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 07/24/2017] [Indexed: 06/07/2023]
Abstract
Multi-watt continuous-wave room temperature operation with efficiency exceeding 10% has been demonstrated for quantum cascade lasers essentially in the entire mid-wave and long-wave infrared spectral regions. Along with interband cascade lasers, these devices are the only room-temperature lasers that directly convert electrical power into mid- and long-infrared optical power. In this paper, we review the progress in high-power quantum cascade lasers made over the last 10 years. Specifically, an overview of the most important active region, waveguide, and thermal design techniques is presented, and various aspects of die packaging for high-power applications are discussed. Prospects of power scaling with lateral device dimensions for reaching optical power level in the range from 10 W to 20 W are also analyzed. Finally, coherent and spectral beam-combining techniques for very high-power infrared platforms are discussed.
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Bismuto A, Bidaux Y, Blaser S, Terazzi R, Gresch T, Rochat M, Muller A, Bonzon C, Faist J. High power and single mode quantum cascade lasers. OPTICS EXPRESS 2016; 24:10694-10699. [PMID: 27409890 DOI: 10.1364/oe.24.010694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present a single mode quantum cascade laser with nearly 1 W optical power. A buried distributed feedback reflector is used on the back section for wavelength selection. The laser is 6 mm long, 3.5 μm wide, mounted episide-up and the laser facets are left uncoated. Laser emission is centered at 4.68 μm. Single-mode operation with a side mode suppression ratio of more than 30 dB is obtained in whole range of operation. Farfield measurements prove a symmetric, single transverse-mode emission in TM00-mode with typical divergences of 41° and 33° in the vertical and horizontal direction respectively. This work shows the potential for simple fabrication of high power lasers compatible with standard DFB processing.
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Fordell T, Wallin AE, Lindvall T, Vainio M, Merimaa M. Frequency-comb-referenced tunable diode laser spectroscopy and laser stabilization applied to laser cooling. APPLIED OPTICS 2014; 53:7476-7482. [PMID: 25402914 DOI: 10.1364/ao.53.007476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Laser cooling of trapped atoms and ions in optical clocks demands stable light sources with precisely known absolute frequencies. Since a frequency comb is a vital part of any optical clock, the comb lines can be used for stabilizing tunable, user-friendly diode lasers. Here, a light source for laser cooling of trapped strontium ions is described. The megahertz-level stability and absolute frequency required are realized by stabilizing a distributed-feedback semiconductor laser to a frequency comb. Simple electronics is used to lock and scan the laser across the comb lines, and comb mode number ambiguities are resolved by using a separate, saturated absorption cell that exhibits easily distinguishable hyperfine absorption lines with known frequencies. Due to the simplicity, speed, and wide tuning range it offers, the employed technique could find wider use in precision spectroscopy.
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Jung S, Jiang A, Jiang Y, Vijayraghavan K, Wang X, Troccoli M, Belkin MA. Broadly tunable monolithic room-temperature terahertz quantum cascade laser sources. Nat Commun 2014; 5:4267. [DOI: 10.1038/ncomms5267] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 05/30/2014] [Indexed: 11/09/2022] Open
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Weis P, Garcia-Pomar JL, Rahm M. Towards loss compensated and lasing terahertz metamaterials based on optically pumped graphene. OPTICS EXPRESS 2014; 22:8473-8489. [PMID: 24718220 DOI: 10.1364/oe.22.008473] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We evidence by numerical calculations that optically pumped graphene is suitable for compensating inherent loss in terahertz (THz) metamaterials. We calculate the complex conductivity of graphene under optical pumping and determine the proper conditions for terahertz amplification in single layer graphene. It is shown that amplification in graphene occurs up to room temperature for moderate pump intensities at telecommunication wavelength λ = 1.5 μm. Furthermore, we investigate the coupling between a plasmonic split ring resonator (SRR) metamaterial and optically pumped graphene at a temperature T = 77 K and a pump intensity I = 300 mW/mm(2). We find that the loss of a SRR metamaterial can be compensated by optically stimulated amplification in graphene. Moreover, we show that a hybrid material consisting of asymmetric split-ring resonators and optically pumped graphene can emit coherent THz radiation at minimum output power levels of 60 nW/mm(2).
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