Semiconductor Laser Engineering, Reliability and Diagnostics: A Practical Approach to High Power and Single Mode Devices

Chapter 9

Novel diagnostic data for diverse laser temperature effects; dynamic laser degradation effects; and mirror temperature maps

9.1 Thermoreflectance microscopy for diode laser diagnostics

9.1.1 Motivation

9.1.2 Concept and signal interpretation

9.1.3 Reflectance–temperature change relationship

9.1.4 Experimental details

9.1.5 Potential perturbation effects on reflectance

9.2 Thermoreflectance versus optical spectroscopies

9.2.1 General

9.2.2 Comparison

9.3 Lowest detectable temperature rise

9.4 Diode laser mirror temperatures by micro-thermoreflectance

9.4.1 Motivation

9.4.2 Dependence on number of active quantum wells

9.4.3 Dependence on heat spreader

9.4.4 Dependence on mirror treatment and coating

9.4.5 Bent-waveguide nonabsorbing mirror

9.5 Diode laser mirror studies by micro-thermoreflectance

9.5.1 Motivation

9.5.2 Real-time temperature-monitored laser degradation

9.5.3 Local optical probe

9.6 Diode laser cavity temperatures by micro-electroluminescence

9.6.1 Motivation

9.6.2 Experimental details – sample and setup

9.6.3 Temperature profiles along laser cavity

9.7 Diode laser facet temperature – two-dimensional mapping

9.7.1 Motivation

9.7.2 Experimental concept

9.7.3 First temperature maps ever

9.7.4 Independent temperature line scans perpendicular to the active layer

9.7.5 Temperature modeling

References

Introduction

The main focus of this chapter is on a detailed description of the fundamental concept, physical realization, diverse applications, and results of the ...