The market for augmented reality (AR) glasses using laser diodes is forecast anticipated to grow by nearly 100 times over the next ten years, and TDK aims to tap into that market.
The Full Colour Laser Module uses a planar lightwave circuit (PLC) from NTT to combine each colour into one optical path. The PLC and three bare laser chips are used in a new sub-assembly construction which requires fewer points to align the position and achieve the smaller size, one tenth the size of a conventional module.
“To demonstrate, we have mounted our Full Colour Laser Module in the RETISSA Display 2, which is a pair of AR glasses from QD Laser,” said Michal Chinn Senior Vice President for Information & Communication Technology at TDK Americas. “In addition to AR and VR glasses, other applications for our Full Colour Laser Module are femto projectors and head-up displays for automobiles.”
“Currently, we envision using a flexible printed circuit (FPC) connection, which is 8.0 mm long, including the terminal. The full colour laser module is extremely light, weighing only 0.35g. All three laser diodes are mounted, with the wavelength of the red laser diode at 636 nm, green at 520 nm, and blue at 455 nm, with the output power of each colour under 5mW,” he said.
The module is equipped with a photodetector and a thermistor to monitor the internal temperature of the unit and prevent overheating.
The structure of the new sub-assembly also requires high-precision alignment, and TDK’s high-speed, automated technology transfers the laser chip, aligns it at high speed and high accuracy, and bonds it to the PLC. This process is performed automatically in five seconds, roughly 150 times faster than conventional modules.
TDK will start supplying samples later in 2021, with production beginning in 2023.