The blue and violet laser beams are pretty useful in the micro-lithography, massive storage device and biomedical instruments. Also it is attracting more interests in the fiber sensing application because of its wavelength. The coupling from the blue and violet laser diode to a fiber still suffers from low coupling efficiency and instability. In Blue Sky Research, we utilized patented microlens technology to facilitate the coupling for 405nm laser diode and got as high as more than 70% efficiency with superior stability. It is an ideal fiber-coupled source for various kinds of application and accommodate wavelength from 375nm to 440nm. The design and the testing are reported in this paper.
"Fiber coupling of 405-nm laser diode with μlens technology", Proc. SPIE 5272, Industrial and Highway Sensors Technology, (8 March 2004); doi: 10.1117/12.514891; https://doi.org/10.1117/12.514891