7 November 2016

Osram presents prototype multi-channel laser for scanning LIDAR in self-driving cars

In booth 107 (Hall A3) at the electronica 2016 trade fair in Munich (8-11 November), Osram Opto Semiconductors GmbH of Regensburg, Germany is showcasing a prototype four-channel laser that is said to take LIDAR (light detection and ranging) systems for autonomous or semi-autonomous driving a step closer.

With an extremely short pulse length and four parallel output channels, the prototype laser offers new options for detecting objects and a unique vertical detection zone, says Osram. This can be used for the first time in scanning LIDAR sensors based on micro-electro-mechanical systems (MEMS). Such solutions do not need a mechanism to re-direct the laser beam, so they are less susceptible to wear and tear. Together with Innoluce (an Infineon Technologies AG company and specialist in laser scanner technology) Osram says that it is showcasing what the future of LIDAR systems may look like.

LIDAR sensors are an essential element in future fully autonomous or semi-autonomous self-driving cars. Operating on the principle of time-of-flight measurement, a very short laser pulse is transmitted, hits an object, is reflected and detected by a sensor. From the time-of-flight of the laser beam it is possible to calculate the distance to the object. Scanning LIDAR systems scan the surroundings of the car horizontally with a laser beam across a certain angular segment and produce a high-resolution 3D map of the environment. In most cases, the laser beams in existing scanning LIDAR systems are deflected via mechanical moving mirrors. Some solutions make use of several laser diodes mounted one on top of the other to extend the vertical field of view.

Four-channel laser bar simplifies adjustment

Osram's four-channel LIDAR laser consists of a laser bar with four individually controllable laser diodes and a control circuit integrated in the module. The entire module is surface-mountable, which reduces assembly costs and the time needed for fine adjustment at the customer.

To create the laser bar, four laser diodes are produced next to each other in a single production step so they are precisely aligned to each other and can be individually controlled. "The new laser is a bar consisting of four laser diodes that are separated in the production process but are not individual diodes," says product manager Sebastian Bauer. "The result is a laser that emits four perfectly parallel beams," he adds. "Our customers no longer have to spend time laboriously adjusting the individual light sources."

Greater optical output, extremely short pulse length

For the new laser Osram has boosted the maximum optical output of its 905nm-wavelength nanostack pulse laser diodes by about 10W to 85W at 30A per channel.

Also, the pulse length has been shortened from 20ns to less than 5ns. The short pulse length and the small duty cycle of 0.01% ensure that, even at such high outputs, the requirements of the relevant eye-safety standards are met. With an operating voltage of 24V the laser also meets the requirements for use in vehicles.

First laser for use with MEMS

Due to the short pulse lengths, the four-channel LIDAR laser for the first time enables a scanning LIDAR system to be produced in which the light beam is deflected via MEMS. The 2.7mm x 2.3mm MEMS chip is operated at up to 2kHz and has been developed by Innoluce B.V. of Nijmegen, The Netherlands (which was acquired by Germany's Infineon in October). The overall system covers a field of view of 120° horizontal and 20° vertical (with a resolution of 0.1° horizontal and 0.5° vertical). In daylight the range for detecting vehicles is at least 200m and for pedestrians 70m. The demonstrator presented at electronica will have slightly different properties.

Pulse laser diodes from Osram Opto have been in use in cars for more than ten years, e.g. for time-of-flight (TOF) measurements in adaptive cruise control (ACC) systems and for emergency brake assist systems. This latest addition to the product portfolio aims to support the many new developments in sensors for self-driving cars. Samples of the new four-channel LIDAR laser will be available from early summer 2017, with market launch planned for 2018.

Tags: Osram

Visit: www.osram-os.com

Visit: www.innoluce.com