Development of a compact deep-ultraviolet laser source for precision microstructure measurement

Dr. Maki Kushimoto

Dr. Maki Kushimoto
Associate Professor/ Lecturer
Graduate School of Engineering, Nagoya University

*The organization and the title are those when awarded

Research summary

In this study, Dr. Kushimoto has demonstrated a compact deep ultraviolet semiconductor laser that can be integrated into high-resolution and high-precision measurement systems, supporting technological innovations in the semiconductor industry where miniaturization is advancing. Furthermore, she has successfully achieved room temperature continuous wave lasing.
Laser light is used in non-contact and non-destructive optical analysis and measurement techniques. Laser light with shorter wavelengths can detect finer structures, making short-wavelength laser light sources increasingly important. Semiconductor lasers have been widely used as compact, high-efficiency, and low-cost light sources in inspection systems. However, there have been many challenges in realizing semiconductor lasers that emit deep ultraviolet light.

Therefore, Dr. Kushimoto succeeded in realizing a deep ultraviolet semiconductor laser through the reduction of defect density in AlGaN using single-crystal AlN substrates and the use of a conductivity control technique different from conventional methods, involving pulse current injection. Furthermore, she constructed a measurement system for comprehensive evaluation and revealed that the deterioration of device performance is primarily caused by defect formation. Dr. Kushimoto proposed a method to suppress the concentration of shear stress through shape control of the laser crystal. As a result, she achieved a room temperature continuous wave lasing that operates at one-tenth of the initial power. This achievement greatly contributes to the practical application of deep ultraviolet semiconductor laser light sources.

Therefore, Dr. Kushimoto succeeded in realizing a deep ultraviolet semiconductor laser through the reduction of defect density in AlGaN using single-crystal AlN substrates and the use of a conductivity control technique different from conventional methods, involving pulse current injection. Furthermore, she constructed a measurement system for comprehensive evaluation and revealed that the deterioration of device performance is primarily caused by defect formation. Dr. Kushimoto proposed a method to suppress the concentration of shear stress through shape control of the laser crystal. As a result, she achieved a room temperature continuous wave lasing that operates at one-tenth of the initial power. This achievement greatly contributes to the practical application of deep ultraviolet semiconductor laser light sources.

Introduction to Research