TDK launches ultra-small full-color laser module

     The TDK full-color laser module is equipped with red, green and blue lasers, but its size is less than a coin. When these three colors are combined, a full-spectrum color palette can be created, including yellows, purples, and even the hard-to-produce white. For demonstration, TDK installed this module on RETISSA Display 2, an AR glasses from QD Laser. In addition to AR/VR glasses, the module can also be used in femtosecond projectors and automotive head-up displays

     The prototype of TDK's full-color laser module is compact in size, 6.7mm long, 5.5mm wide and 2.7mm high. The current assumption is to use a flexible printed circuit board with a length of 8 mm including the terminals. The full-color laser module is very light, weighing only 0.35g, and is equipped with three laser diodes. The wavelength of the red laser diode is 636nm, the wavelength of the green laser diode is 520nm, and the wavelength of the blue laser diode is 455nm. The output power of each color is All are below 5mW. The module is also equipped with a light spot detector and a thermistor to monitor the internal temperature of the unit and prevent overheating.

     Achieving this ultra-compact light source faces two technical challenges: miniaturization and production time reduction using planar lightwave circuits. In traditional RGB laser modules, each color is produced by a set of mirrors and lenses that combine into a single light path, resulting in a large module size. In contrast, TDK's full-color laser modules use NTT planar lightwave circuits that combine each color into a single light path. In this new assembly structure, PCL and bare laser chips are used, allowing fewer points to be used for alignment. Combining the above factors, the size of this module is 10 times smaller than that of traditional modules.

     The structure of the new components also requires high-precision alignment, and TDK's high-speed automation technology enables high-speed and precise alignment of the laser chips when transferring them and sticking them to the PLC. The process is completed automatically within 5 seconds, which is about 150 times faster than the production efficiency of conventional modules.