Japanese newest VCSEL module technology improves output of spatial recogntion and ranging sytems

Japanese ROHM company achieves greater accuracy in spatial recognition and distance measuring by VCSEL technology and Time Of Flight (TOF) systems.

As we know, VCSEL technology has been used in laser light sources for spatial recognition in tablets and facial recognition in smartphones. The increasing application of Automated Guided Vehicles (AGVs) and industrial inspection systems with gesture and shape recognition makes the market requirement for VCSEL bigger.

Besides, for self-driving applications that need automation, higher accuracy sensing asks for shorter pulse drive and higher output for the light source.

As for old VCSEL-equipped laser light sources, both VCSEL device and MOSFET for driving the light source are separately installed on the board. The wiring length (parasitic inductance) between products has an unintended effect on the light source output and drive time, which makes it hard to achieve a light source for higher output and short pulses required for high accuracy sensing.

The new VCSEL module technology developed by ROHM can achieve modularizing the VCSEL and MOSFET elements into a single package. By minimizing the wiring length between elements, the performance of each element is perfectly improved so as to result in a light source capable of short pulse drive (under 10ns). In this way, the newest technology can reduce susceptibility to external noise from sunlight while achieving up to 30% higher output than conventional solutions.

Consuquently, based on ROHM’s VCSEL module technology in spatial recognition and ranging systems comprised 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 more than 30% than that by old VCSEL module technology , which in turn helps improved accuracy in TOF systems.