レーザー点火向け高出力VCSELモジュール

抄録

An 808nm-range high-power fiber-coupled VCSEL module was developed for laser ignition system. The fabricated VCSEL module was very compact as about 100 mm×100 mm including a cooling unit, and stable operation is possible by air cooling. The light power of VCSEL array and the fiber-coupled module were 311 W and 204 W under the quasi continuous wave operation (pulse width 500 μs, pulse cycle 20 Hz), respectively. This output power is the largest one that was reported to date as a fiber-coupled VCSEL module. The oscillation spectrum width of module was as narrow as 1.7 nm in full width at half maximum at the above output, and the temperature dependence of wavelength was 0.05 nm/K. By exciting Nd³⁺: YAG / Cr⁴⁺: YAG composite ceramics using this VCSEL module, Q switched laser output of 2.5 mJ×4 pulse which was required for engine operation was obtained.