Osram Opto Semiconductors fast laser diode

A high-power fast laser diode from Osram Opto Semiconductors provides light for the new 3D camera from Swedish manufacturer Fotonic. The diode, that facilitates range finding of moving objects with good depth resolution at high-speed video rates, has been developed specifically for 3D cameras.

The laser diode provides high optical power of about 0.5 W, even when in continuous wave operation. With a wavelength of about 845 nm, the light is barely visible to the human eye but is well within the sensitivity range of the camera chip.

The camera superimposes a two-dimensional picture with information on the range and surface profile of an object. Industrial applications for this type of system include gauging fluid levels, grading objects according to size or shape and obtaining reliable stereoscopic information for controlling robot arms.

The laser diode transmits a light pulse that is reflected back from the target. Each of the 120x160 pixels of the camera chip records the distance to the object by measuring a respective phase shift compared with the emitted light pulse.

The precision of this distance measurement and the range of the sensor increase with the modulating frequency of the light source.

The device is modulated with 44 MHz and, within the range of 0.1 to 7 m, that enables the camera to measure distances with an accuracy of up to 30 mm.