Kazuhito Tajima

Title: Kazuhito Tajima: Optical Communications and Semiconductor Inventions.

Introduction

Kazuhito Tajima is an inventor based in Tokyo, Japan, whose work includes technologies for optical communications and semiconductor devices. His listed portfolio includes 11 patents, and his work is associated with NEC Corporation.

Latest Patents

Tajima’s listed inventions include a wavelength converter designed for stable operation in long-distance, high-capacity optical communications. The device uses a nonlinear waveguide and a delay interference circuit with two optical paths of different lengths. Its design relates the coherent length of the continuous-wave light source to the optical path difference, supporting wavelength conversion with a relatively simple configuration.

Another listed invention concerns a semiconductor nonlinear waveguide and an all-optical switch. The waveguide uses a pin structure with InGaAsP and InP layers, while electrical short-circuiting between the cladding layers enables a built-in electrostatic field. This field can shorten the effective carrier lifetime, helping the switch operate at a higher repetition frequency without requiring a constant-voltage power supply.

Career Highlights

Tajima’s patent work reflects an emphasis on optical switching, wavelength conversion, and semiconductor waveguide design. These technologies address practical challenges in controlling optical signals and improving the performance of communication systems.

Collaborations

The supplied information identifies Shigeru Nakamura and Yoshiyasu Ueno as Tajima’s coworkers. Their names are associated here as collaborators, though specific joint projects are not provided.

Conclusion

Kazuhito Tajima’s listed patents highlight contributions to optical communication and semiconductor switching technologies, with a focus on stable wavelength conversion and faster all-optical operation.