Time resolved Fabry-Perot measurements of cavity temperature in pulsed QCLs

Download

10.1364OE.26.006572.pdf

Date

2018-3-5

Author

Gundogdu, S.
Pisheh, H. S.
Demir, A.
Gunoven, M.
Aydinli, A.
Sirtori, C.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

212
views

127
downloads

Temperature rise during operation is a central concern of semiconductor lasers and especially difficult to measure during a pulsed operation. We present a technique for in situ time-resolved temperature measurement of quantum cascade lasers operating in a pulsed mode at similar to 9.25 mu m emission wavelength. Using a step-scan approach with 5 ns resolution, we measure the temporal evolution of the spectral density, observing longitudinal Fabry-Perot modes that correspond to different transverse modes. Considering the multiple thin layers that make up the active layer and the associated Kapitza resistance, thermal properties of QCLs are significantly different than bulk-like laser diodes where this approach was successfully used. Compounded by the lattice expansion and refractive index changes due to time-dependent temperature rise, Fabry-Perot modes were observed and analyzed from the time-resolved emission spectra of quantum cascade lasers to deduce the cavity temperature. Temperature rise of a QCL in a pulsed mode operation between -160 degrees C to -80 degrees C was measured as a function of time. Using the temporal temperature variations, a thermal model was constructed that led to the extraction of cavity thermal conductivity in agreement with previous results. Critical in maximizing pulsed output power, the effect of the duty cycle on the evolution of laser heating was studied in situ, leading to a heat map to guide the operation of pulsed lasers. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Subject Keywords

QUANTUM-CASCADE LASERS, THERMAL IMPEDANCE, SPECTROSCOPY

URI

https://hdl.handle.net/11511/51690

Journal

Optics Express

DOI

https://doi.org/10.1364/oe.26.006572

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

Thermal characterisation of quantum cascade lasers with Fabry Perot modes Gundogdu, Sinan; Pisheh, Hadi Sedaghat; Demir, Abdullah; Guenoven, Mete; AYDINLI, ATİLLA; Sirtori, Carlo (2018-04-26) Quantum cascade lasers are coherent light sources that rely on intrersubband transition in periodic semiconductor quantum well structures. They operate at frequencies from mid-infrared to terahertz. In cases of long wavelength and typical low thermal conductivity of the active region, temperature rise in the active region during operation is a major concern. Thermal conductivity of QCL epi-layers differ significantly from the values of bulk semiconductors and measurement of the thermal conductivity of epi-l...
Time resolved spectroscopy of laser induced air plasma Kurt, Mustafa; Esendemir, Akif; Department of Physics (2007) The laser beam interaction with matter and the plasma generation have been studied for many years. In some applications what is really important is to understand the composition and the temporal evolution of the species in the interested medium. In this thesis, time resolved optical spectroscopy was employed to understand the evolution of the plasma which is produced by interaction of Infrared (1.064 m) laser beam with air. In this thesis, a new technique is suggested to analyze the time evolution of laser ...
Pumping chamber design in diode pumped solid-state lasers for maximum system efficiency and minimum optical distortion Zengin, Kubilay; Sayan, Gönül; Yelen, Kuthan; Department of Electrical and Electronics Engineering (2013) The beam quality and the system efficiency of a diode-pumped solid-state laser source are directly related to the thermal profile inside the laser crystal. The thermal profile in a laser crystal should be made uniform in order to reduce the negative effects of the thermal lens. However, the absorbed pump profile that forms a uniform thermal profile inside the gain medium may adversely affect the system efficiency. In this thesis, a computational and empirical method was developed for designing pumping chamb...
Thermal network method applications to problems related with the thermal analysis of small satellites. Okan, Altuğ; Çelenligil, M. Cevdet; Tekinalp, Ozan; Department of Aeronautical Engineering (2002) In this thesis, the thermal network method is examined in detail and is applied to some problems related with the thermal analysis of small satellites. In satellites, dominant modes of heat transfer are the thermal radiation and conduction. In this research, energy exchanges among the surfaces of satellites are investigated. Also, the radiation exchange factors are determined which are necessary in radiation thermal analyses. A FORTRAN code 'TRANS" is developed. This code uses the thermal network method for...
Time Domain Terahertz Attenuated Total Internal Reflection Spectroscopy Atalar, Ataberk; Altan, Hakan; Department of Physics (2021-7) In this thesis, a Terahertz Time Domain Spectroscopy system based on the Attenuated Total Internal Reflection principle (THz ATR-TDS) was constructed in order to non-destructively evaluate materials which show high absorptive characteristics at THz frequencies and therefore prove other widely used THz transmission spectroscopy methods ineffective. The response of the system without a sample differs in amplitude and in time scale when compared to a sample measurement due to the real and imaginary parts of th...

Citation Formats

S. Gundogdu, H. S. Pisheh, A. Demir, M. Gunoven, A. Aydinli, and C. Sirtori, “Time resolved Fabry-Perot measurements of cavity temperature in pulsed QCLs,” Optics Express, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/51690.