Research Of Semiconductor Laser Optical Coatings Technology

In this paper we discussed how to plate the optical film in high power CW 808nm laser diode, 980nm CW VCSEL and 1064nm CW and QCW laser array module. Optical film is the key technology of semiconductor laser and its performance will affect power output, power efficiency, reliability and stability. Firstly, cavity surface film of 808nm high power laser diode was developed. Cavity surface films of HfO2/SiO2 was adopted here. Single layer Al2O3 was imported between cavity surface film and substrate, which resolve problem of adhesion between cavity surface film and substrate. The slope efficiency was improved from 50.2% to 90.4% after film was plated, conversion efficiency was improved from 22.2% to 9.8% and the maximum output power is 1.9W. The damage threshold of this kind of film is superior to other kind films, which shows that this method is fit for large batch production of 808nm diode lasers. We studied deeply cavity surface film of 1064nm high power diode laser and developed CW 1060nm and QCW 1050nm output laser array modules. CW 1064nm chip has a width of 1cm, length of 200μm, cavity length of 1200μm and a filling factor of 50%. The maximum output power is 68.5W, the half width is 9nm at room temperature. QCW 1050nm laser module has a width of 1cm, cavity length of 1200μm and filling factor is 82.5%. The maximum output power reached 88.6W and half width is 4.2nm at pulse width of 100μs, frequency of 1000Hz and current of 100A. 1064nm high power semiconductor laser has not been reported in our country. Anti-reflection film of 980nm high power VCSEL was developed. Output power of VCSEL with different diameter (200μm-800μm) increased 6% after film was plated. Output power with diameter of 500-700μm reached 1.95W and the result is best level up to now. We use transfer matrix to calculate the optical performance of anti-reflection and high reflection films for regular and un-regular film systems. For the first time, we adopted contrary matrix method to calculate electrical field distribution of cavity surface film and obtained distribution curves of electrical distribution. The design and optimization of all films were realized through the two programs. We designed cavity surface film of high damage threshold. Additionally, we used clamp self-made to settle some difficult problems such as calibration of cavity surface film, film width controlling, film uniformity and pollution and damage of film.