News: Optoelectronics
30 November 2020
ROHM develops VCSEL module technology
Japan-based ROHM says that its newly developed vertical-cavity surface-emitting laser (VCSEL) technology achieves greater accuracy in spatial recognition and distance measuring systems by using time-of-flight (TOF) systems.
VCSEL module technology has become popular in recent years with the adoption of laser light sources for spatial recognition in tablets and facial recognition in smartphones. Also, with the emergence of automated guided vehicles (AGVs) and industrial inspection systems utilizing gesture and shape recognition, demand for VCSELs is expected to rise.
Meanwhile, for applications that require automation, shorter pulse drive and higher output for the light source are required to achieve higher-accuracy sensing.
Conventionally, in VCSEL-equipped laser light sources, both the VCSEL and the MOSFET for driving the light source are individually mounted on the board. Consequently, the wiring length (parasitic inductance) between products has an unintentional effect on the light source output and drive time, making it difficult to achieve a light source that provides the high output and short pulses needed for high-accuracy sensing.
ROHM says that its new VCSEL module technology makes it possible to modularize the VCSEL and MOSFET elements into a single package. By minimizing the wiring length between elements, the performance of each element is maximized, resulting in a light source capable of short pulse drive (under 10ns) that reduces susceptibility to external noise from sunlight while enabling up to 30% higher output over conventional solutions, reckons ROHM.
As a result, when evaluating its VCSEL module technology in spatial recognition and ranging systems consisting of a control IC, TOF sensor (light receiving element) and laser light source (VCSEL module), the amount of light reflected to the TOF sensor is increased by 30% over conventional configurations, contributing to improved accuracy in TOF systems, claims ROHM.
In March, ROHM plans to release its new VCSEL module for AGVs in the industrial market and facial recognition systems for mobile devices requiring high-accuracy sensing. The firm will also continue to develop high-output lasers for light detection & ranging (LiDAR) in vehicles and other applications.
