Takeshi Segi

Novel 1.8-μm-band light sources composed of thulium-doped fiber for in vivo imaging

We have developed a single mode fiber-light source at 1.8um band, which composes of thulium (Tm)-doped silica fiber and optical devices used in telecommunication fields. This laser can be operated as a laser and broadband light source selectively. The laser wavelength is tuned from 1765nm to 1812nm by adjusting an angle of a built-in band pass filter (BPF). A maximum output power is 115mW at 1812nm, in the case that pump power is 363mW. The broadband light source has a maximum power of 10mW, the peak wavelength of 1840nm and the full width at half maximum of 50nm. By using these light sources, we have succeeded in obtaining images of test target by observing reflected light through opaque liquid.

Silica-based composite fiber amplifier with 1480-1560 nm seamless gain-band

All silica-based fiber amplifier with a cascaded configuration of a 980 nm-pumped EDFA and a gain-shifted TDFA has realized a seamless gain-band over the wavelength region of 1480-1560 nm. A gain over 10 dB and NF under 7.5 dB have been achieved.

Diode-pumping high-power Q-switched fiber laser at 2.8 /spl mu/m

A Q-switched high-power fiber laser at 2.8 /spl mu/m has been developed with a high power pumping laser diode array and an Er-doped double-clad fiber. Peak power over 50 W and pulse energy of 31 /spl mu/J is achieved.