Driverless Automotive Lasers

As early as ten years ago, the infrared laser diode used in the world's first automotive laser sensor came from Osram Opto Semiconductors. As one of the world's first suppliers of powerful infrared LEDs (IRED), Osram Opto Semiconductors has also witnessed the birth and development of camera systems using auxiliary infrared lighting. Up to now, these optical sensors have been applied to a variety of individual auxiliary systems; in the future, they will also play an important role in the integration of other technologies for automatic driving. With optical sensors, driverless cars can capture surrounding objects and use the collected data to make decisions.

The LIDAR sensor is based on a fast infrared pulsed laser diode and captures the distance between the object and the car. So far, this technology has been successfully used in auxiliary systems such as adaptive cruise control systems; in the future, it will play a pivotal role in the development of driverless cars.

Powerful laser diode for LIDAR sensor

The LIDAR sensor (LIDAR) functions to detect the objects around it and capture the distance between them and the sensor. To accomplish this, one laser emits very short pulses of light, while another fast detector measures the time it takes for light to travel between the sensor and the object, and then determines the relative distance between the object and the car by the propagation time of the signal. mobile. LIDAR sensors are currently used mainly for adaptive cruise control systems and emergency brake assist systems. Important standards for laser sources include pulse-mode output over long distances, fast switching times, and applicability in automotive applications. With respect to automotive LIDAR sensors, OSRAM has successfully developed infrared pulsed laser diodes with a wavelength of 905 nm, which emit light that is invisible to the human eye. The laser chip includes three emission centers that use nanostack technology to achieve optical pulse power in excess of 75W. The SPLLL90_3 laser diode has an integrated driver circuit that supports a pulse time of approximately 20 nanoseconds.

IRED for record-setting camera systems

The camera system is used to generate images and video, and can extract environmental information from it through intelligent image processing functions. If you use a camera sensor to detect infrared light that is not visible to the human eye and illuminate the scene, you can greatly improve the image quality at night. The Night Vision Assist System is a good example. It can illuminate streets about 150 meters away by infrared light. These systems typically require powerful IREDs with the appropriate wavelengths to meet the needs of continuous operation. OSRAM Opto Semiconductors is the current record holder thanks to the IRED with a wavelength of 850 nm. Oslon Black SFH 4715A can achieve about 800mW light output at 1A operating current with up to 48% efficiency. It is the IRED with the highest light efficiency under the same working conditions. In order to achieve higher values, Osram even has two emitters for each chip in the stack. It is precisely because of this that the Oslon Black SFH 4715AS can operate continuously at 1A for a light output of 1370mW.

Escort the driver

The development of these technologies has also benefited in-vehicle applications. One example is the use of a camera to detect driver alertness. The above information is usually needed when the automatically controlled vehicle is safely switched back to manual control (if required). The in-vehicle camera system requires the use of an IRED with a wavelength of 940 nm because the light at this wavelength is not noticeable to the human eye even at night. OSRAM has upgraded its 850nm high-efficiency chip technology, and the light output of the 940nm stack chip is closer to the 1W record. The typical light output of the Oslon Black SFH 4725S at 1A is 990mW.

All in all, the continuous development of optical sensor light sources will play a crucial role in the development of automatic transportation. Existing stand-alone auxiliary systems will be integrated into larger and more complete systems, which will in turn increase the requirements for individual sensors.