Junichi Nishimae

24-mJ, 2-kHz pulse generation with a Q-switched Nd:YAG laser oscillator and fiber amplifier hybrid system

In this paper, we study the pulse generation with the experimental apparatus consists of an in-house Q-switched Nd:YAG rod laser oscillator and a Yb-doped fiber amplifier. As a result, we obtained an average output power of 48 W with a typical clean Q-switched pulse waveform at a repetition rate of 2 kHz. This is, to our knowledge, the highest pulse energy obtained with a solid-state-laser oscillator and a fiber-based amplifier scheme.

400-W Diode-Pumped Solid-State Green laser

More than 400-W green laser power was generated by second-harmonic generation of a Q-switched diode-pumped Nd: YAG laser at a repetition rate of 8 kHz. This power is, to our knowledge, highest in solid-state green lasers.

Effective fabrication of long period fiber grating with high contrast stripe beam by HOE

We have developed a novel illumination technique to fabricate a long period fiber grating (LPFG) in which a stripe-line beam profile is generated with a computer generated holographic optical element (HOE). We found that the illumination of high contrast stripe beam profile is effective in reducing the UV exposure energy necessary for the fabrication of LPFG.