scholarly journals Application of High-Speed Quantum Cascade Detectors for Mid-Infrared, Broadband, High-Resolution Spectroscopy

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5706
Author(s):  
Tatsuo Dougakiuchi ◽  
Naota Akikusa
Keyword(s):  
High Resolution ◽  
High Speed ◽  
Dynamic Range ◽  
Molecular Spectroscopy ◽  
Low Noise ◽  
Heterodyne Detection ◽  
High Resolution Spectroscopy ◽  
Mid Infrared ◽  
Quantum Cascade ◽  
Noise Characteristics

Broadband, high-resolution, heterodyne, mid-infrared absorption spectroscopy was performed with a high-speed quantum cascade (QC) detector. By strictly reducing the device capacitance and inductance via air-bridge wiring and a small mesa structure, a 3-dB frequency response over 20 GHz was obtained for the QC detector, which had a 4.6-μm peak wavelength response. In addition to the high-speed, it exhibited low noise characteristics limited only by Johnson–Nyquist noise, bias-free operation without cooling, and photoresponse linearity over a wide dynamic range. In the detector characterization, the noise-equivalent power was 7.7 × 10−11 W/Hz1/2 at 4.6 μm, and it had good photoresponse linearity up to 250 mW, with respect to the input light power. Broadband and high-accuracy molecular spectroscopy based on heterodyne detection was demonstrated by means of two distributed-feedback 4.5-μm QC lasers. Specifically, several nitrous oxide absorption lines were acquired over a wavelength range of 0.8 cm−1 with the wide-band QC detector.

Ultimate response time in mid-infrared high-speed low-noise quantum cascade detectors

2021 ◽  
Vol 118 (4) ◽  
pp. 041101
Author(s):  
Tatsuo Dougakiuchi ◽  
Akio Ito ◽  
Masahiro Hitaka ◽  
Kazuue Fujita ◽  
Masamichi Yamanishi
Keyword(s):  
Response Time ◽  
High Speed ◽  
Low Noise ◽  
Mid Infrared ◽  
Quantum Cascade

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

scholarly journals Direct Observation of Terahertz Frequency Comb Generation in Difference-Frequency Quantum Cascade Lasers

2021 ◽  
Vol 11 (4) ◽  
pp. 1416
Author(s):  
Luigi Consolino ◽  
Malik Nafa ◽  
Michele De Regis ◽  
Francesco Cappelli ◽  
Saverio Bartalini ◽  
...  
Keyword(s):  
Near Infrared ◽  
Quantum Cascade Lasers ◽  
Molecular Spectroscopy ◽  
Frequency Comb ◽  
Frequency Standard ◽  
Difference Frequency ◽  
Heterodyne Detection ◽  
Optical Rectification ◽  
Total Output ◽  
Quantum Cascade

Terahertz quantum cascade laser sources based on intra-cavity difference frequency generation from mid-IR devices are an important asset for applications in rotational molecular spectroscopy and sensing, being the only electrically pumped device able to operate in the 0.6–6 THz range without the need of bulky and expensive liquid helium cooling. Here we present comb operation obtained by intra-cavity mixing of a distributed feedback laser at λ = 6.5 μm and a Fabry–Pérot device at around λ = 6.9 μm. The resulting ultra-broadband THz emission extends from 1.8 to 3.3 THz, with a total output power of 8 μW at 78 K. The THz emission has been characterized by multi-heterodyne detection with a primary frequency standard referenced THz comb, obtained by optical rectification of near infrared pulses. The down-converted beatnotes, simultaneously acquired, confirm an equally spaced THz emission down to 1 MHz accuracy. In the future, this setup can be used for Fourier transform based evaluation of the phase relation among the emitted THz modes, paving the way to room-temperature, compact, and field-deployable metrological grade THz frequency combs.

scholarly journals Measurement of synchrotron-radiation-excited Kossel patterns

2016 ◽  
Vol 23 (1) ◽  
pp. 214-218 ◽  
Author(s):  
G. Bortel ◽  
G. Faigel ◽  
M. Tegze ◽  
A. Chumakov
Keyword(s):  
High Resolution ◽  
Dynamic Range ◽  
Structural Information ◽  
Photon Counting ◽  
Spot Size ◽  
Low Noise ◽  
X Rays ◽  
Technical Problems ◽  
Pixel Detectors ◽  
Exciting Beam

Kossel line patterns contain information on the crystalline structure, such as the magnitude and the phase of Bragg reflections. For technical reasons, most of these patterns are obtained using electron beam excitation, which leads to surface sensitivity that limits the spatial extent of the structural information. To obtain the atomic structure in bulk volumes, X-rays should be used as the excitation radiation. However, there are technical problems, such as the need for high resolution, low noise, large dynamic range, photon counting, two-dimensional pixel detectors and the small spot size of the exciting beam, which have prevented the widespread use of Kossel pattern analysis. Here, an experimental setup is described, which can be used for the measurement of Kossel patterns in a reasonable time and with high resolution to recover structural information.

scholarly journals A widely tunable 10-μm quantum cascade laser phase-locked to a state-of-the-art mid-infrared reference for precision molecular spectroscopy

2014 ◽  
Vol 104 (26) ◽  
pp. 264101 ◽  
Author(s):  
P. L. T. Sow ◽  
S. Mejri ◽  
S. K. Tokunaga ◽  
O. Lopez ◽  
A. Goncharov ◽  
...  
Keyword(s):  
Quantum Cascade Laser ◽  
Molecular Spectroscopy ◽  
State Of The Art ◽  
Mid Infrared ◽  
Quantum Cascade

scholarly journals Applications for quantum cascade lasers and detectors in mid-infrared high-resolution heterodyne astronomy

2007 ◽  
Vol 90 (2) ◽  
pp. 187-190 ◽  
Author(s):  
P. Krötz ◽  
D. Stupar ◽  
J. Krieg ◽  
G. Sonnabend ◽  
M. Sornig ◽  
...  
Keyword(s):  
High Resolution ◽  
Quantum Cascade Lasers ◽  
Mid Infrared ◽  
Quantum Cascade ◽  
Cascade Lasers

High-Speed Mid-Infrared Frequency Modulation Spectroscopy Based on Quantum Cascade Laser

2016 ◽  
Vol 28 (16) ◽  
pp. 1727-1730 ◽  
Author(s):  
Chen Peng ◽  
Gang Chen ◽  
Jianping Tang ◽  
Lijun Wang ◽  
Zhongquan Wen ◽  
...  
Keyword(s):  
Quantum Cascade Laser ◽  
Frequency Modulation ◽  
High Speed ◽  
Mid Infrared ◽  
Modulation Spectroscopy ◽  
Quantum Cascade

scholarly journals Searching for H2 emission from protoplanetary disks using near- and mid-infrared high-resolution spectroscopy

2007 ◽  
Vol 3 (S249) ◽  
pp. 359-368
Author(s):  
A. Carmona ◽  
M. E. van den Ancker ◽  
Th. Henning ◽  
Ya. Pavlyuchenkov ◽  
C. P. Dullemond ◽  
...  
Keyword(s):  
Surface Layer ◽  
High Resolution ◽  
Near Infrared ◽  
Protoplanetary Disks ◽  
High Resolution Spectroscopy ◽  
Disk Model ◽  
Mid Infrared ◽  
T Tauri ◽  
Hα Emission ◽  
Ir Emission

AbstractThe mass and dynamics of protoplanetary disks are dominated by molecular hydrogen (H2). However, observationally very little is known about the H2. In this paper, we discuss two projects aimed to constrain the properties of H2 in the disk's planet forming region (R<50AU). First, we present a sensitive survey for pure-rotational H2 emission at 12.278 and 17.035 μm in a sample of nearby Herbig Ae/Be and T Tauri stars using VISIR, ESO's VLT high-resolution mid-infrared spectrograph. Second, we report on a search for H2 ro-vibrational emission at 2.1228, 2.2233 and 2.2477 μm in the classical T Tauri star LkHα 264 and the debris disk 49 Cet employing CRIRES, ESO's VLT high-resolution near-infrared spectrograph.VISIR project: none of the sources show H2 mid-IR emission. The observed disks contain less than a few tenths of MJupiter of optically thin H2 at 150 K, and less than a few MEarth at T>300 K. % and higher T. Our non-detections are consistent with the low flux levels expected from the small amount of H2 gas in the surface layer of a Chiang and Goldreich (1997) Herbig Ae two-layer disk model. In our sources the H2 and dust in the surface layer have not significantly departed from thermal coupling (Tgas/Tdust<2) and the gas-to-dust ratio in the surface layer is very likely <1000.CRIRES project: The H2 lines at 2.1218 μm and 2.2233 μm are detected in LkHα 264. An upper limit on the 2.2477 μm H2 line flux in LkHα 264 is derived. 49 Cet does not exhibit H2 emission in any of observed lines. There are a few MMoon of optically thin hot H2 in the inner disk (∼0.1 AU) of LkHα 264, and less than a tenth of a MMoon of hot H2 in the inner disk of 49 Cet. The shape of the 1–0 S(0) line indicates that LkHα disk is close to face-on (i<35o). The measured 1–0 S(0)/1–0 S(1) and 2–1 S(1)/1–0 S(1) line ratios in LkHα 264 indicate that the H2 is thermally excited at T<1500 K. The lack of H2 emission in the NIR spectra of 49 Cet and the absence of Hα emission suggest that the gas in the inner disk of 49 Cet has dissipated.

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