Researchers Develop High-Power Green Laser Module
January 24, 2012
Prototype module appearance with a dime for size reference Image: Fijitsu
Recently, high-power green lasers have been garnering much attention in many fields, including life sciences and with biomedical and industrial applications. Different from near-infrared lasers for optical communications and red and blue lasers for optical storage, semiconductor lasers provide limited output characteristics in the case of green lasers. Therefore, diode pumped solid state (DPSS) lasers are usually used in applications which require high output power at wavelengths around 530 nm. In these applications, it is imperative to have improved wavelength stability and high-speed modulation capability as well as low power consumption and compact size.
QD Laser developed 1064 nm high-power single-mode lasers optimized for wavelength conversion in collaboration with Fujitsu Laboratories and the Univ. of Tokyo. This development was based on the collective core proprietary technologies of semiconductor crystal growth, precise grating fabrication, and device design technology. Furthermore, the newly developed module assembling technology enables precise integration of the laser chip and wavelength conversion crystal. As a result, a high output power of more than 100 mW at a wavelength of 532 nm from an ultra-compact package of just 0.5 cc was achieved. According to the test results of the prototype module, 100 mW output power was obtained with power dissipation of about 900 mW, which means high wall-plug efficiency of more than 10%. For the optical spectral characteristics, narrow linewidth of less than 0.01 nm with a high side-mode suppression ratio was obtained, which is particularly suitable for precise measurements using an optical interference or high resolution spectroscopy. In addition, confirmation was made of a high-speed optical modulation capability of more than 100 MHz and short pulse of less than 1 nsec operation. This was done with a simple direct current modulation scheme, which showed that it could be effective for time resolved spectroscopy and other fields. These unique characteristics of high-power, high-efficiency, and high-speed modulation with compact package are also expected to apply to future display applications like heads-up displays or ultra-compact mobile projectors, which are attracting much attention and growing in the market.
QD Laser has already started shipping samples of QLD0593-P05, a module with 5 mW output power. In addition, it plans to start shipping high power samples of QLD0593-P50, a module with >50 mW output power, in April, 2012 with mass production commencing from the 4th quarter of 2012.
QD Laser markets 1064 nm band DFB laser modules, mainly for industrial applications including as a seed source for fiber lasers, and has already shipped them to more than 30 companies worldwide. QD Laser's in-house epitaxial growth and grating technology provides the flexibility to handle a wide range of wavelength bands and is now extending the wavelength lineup of DFB laser modules from 1030 to 1300 nm. QD Laser also has the potential to extend wavelength lineup by combining with a wavelength conversion technology in visible wavelength regions like 515 nm and 555 nm for special green laser or 560 nm and 590 nm for yellow to orange colors. QD Laser will continue these unique technical developments to meet market requirements.