Time resolved temperature measurements in a H2 high power pulsed discharge

1998 ◽  
Vol 08 (PR7) ◽  
pp. Pr7-287-Pr7-295 ◽  
Author(s):  
A. Rousseau ◽  
E. Teboul ◽  
P. Leprince
Keyword(s):  
High Power ◽  
Temperature Measurements ◽  
Pulsed Discharge ◽  
Time Resolved

Time-Resolved Microscale Temperature Measurements of High-Power Semiconductor Lasers

2005 ◽  
Author(s):  
Paddy K. L. Chan ◽  
Amul D. Sathe ◽  
Kevin P. Pipe ◽  
Jason J. Plant ◽  
Paul W. Juodawlkis
Keyword(s):  
Surface Temperature ◽  
Temperature Profile ◽  
Semiconductor Lasers ◽  
High Power ◽  
Nondestructive Method ◽  
Temperature Measurements ◽  
Semiconductor Diode ◽  
Nonradiative Recombination ◽  
Time Resolved ◽  
Time Resolved Measurements

Nonradiative recombination and other heat generation processes affect both the performance and lifetime characteristics of semiconductor diode lasers. This is especially true for high-power devices, where facet heating due to nonradiative recombination can lead to catastrophic optical damage (COD). Here we present for the first time temperature measurements of a semiconductor laser in which the surface temperature profile (and hence the current density profile) of the laser is measured as it evolves in time. The laser studied is a λ=1.55μm 1-cm-long InGaAsP/InP watt-class slab-coupled optical waveguide laser (SCOWL). The ridge width of the SCOWLs examined here is approximately 5 μm. Temperature measurements are taken using multiple microthermocouples with sizes less than 20μm. Surface temperature fluctuations in time are seen to be quite large, as high as 20% of the total temperature increase of the device. Time-resolved measurements allow us to see both positive correlation (in which the temperature rises at the same time across an area of the device) as well as negative correlation (in which part of the device gets hot at the same time as another part of the device gets cold). Negative correlations are likely due to facet heating processes which cause bandgap shrinkage and hence increased current flow to a facet, pulling current away from the center of the device. Time-resolved measurements of the surface temperature profile therefore show promise as a nondestructive method for characterizing the failure mechanisms of a laser, as facet damage over time is otherwise very difficult to measure before the COD runaway process destroys the device.

scholarly journals Time-Resolved On-Axis Spectroscopic Stagnation Temperature Measurements in Shock Tunnel Flows

2019 ◽  
Vol 3 (2) ◽  
pp. 6
Author(s):  
Hartmut Borchert ◽  
Stefan Brieschenk ◽  
Berthold Sauerwein
Keyword(s):  
Shock Tunnel ◽  
Temperature Measurements ◽  
Stagnation Temperature ◽  
Time Resolved

Time-Resolved Micro-Raman Thermometry for Microsystems in Motion

2008 ◽  
Vol 130 (12) ◽  
Author(s):  
Justin R. Serrano ◽  
Sean P. Kearney
Keyword(s):  
Microelectromechanical Systems ◽  
Diagnostic Technique ◽  
Temperature Measurements ◽  
Transient Temperature ◽  
Raman Signal ◽  
Periodic Signal ◽  
Fast Time ◽  
Time Resolved ◽  
Microelectromechanical Devices ◽  
Reliable Temperature

Micro-Raman thermometry has been demonstrated to be a feasible technique for obtaining surface temperatures with micron-scale spatial resolution for microelectronic and microelectromechanical systems (MEMSs). However, the intensity of the Raman signal emerging from the probed device is very low and imposes a requirement of prolonged data collection times in order to obtain reliable temperature information. This characteristic currently limits Raman thermometry to steady-state conditions and thereby prevents temperature measurements of transient and fast time-scale events. In this paper, we discuss the extension of the micro-Raman thermometry diagnostic technique to obtain transient temperature measurements on microelectromechanical devices with 100 μs temporal resolution. Through the use of a phase-locked technique we are able to obtain temperature measurements on electrically powered MEMS actuators powered with a periodic signal. Furthermore, we demonstrate a way of obtaining reliable temperature measurements on micron-scale devices that undergo mechanical movement during the device operation.

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