Masaki Ohmura

The dispersion-free filters for DWDM systems using 30 mm long symmetric fiber Bragg gratings

The dispersion-free FBG is designed by applying the optimized cosine-progression to the apodization profile. As experimental results show that it offers the suitable filter, with 25 dB crosstalk, 15 ps group delay, for high bit-rate DWDM systems.

Single-mode 24-fiber connector with GI fiber lens array

A Single-mode 24-fiber connector with GI fiber-lenses is developed. The lenses make it possible to adopt MT-connector based guide-pin-alignment. Insertion loss of 0.54dB on average and loss variation less than 0.08dB under temperature cycling is achieved.

A temperature-insensitive erbium-doped fiber amplifier for terrestrial wavelength-division-multiplexing systems

We have evaluated a variation in the temperature dependence of an erbium-doped fiber gain spectrum by a pump wavelength in the 980-nm band for the first time. By optimizing both the pump wavelength in the 980-nm band and a temperature-sensitive gain flattening filter, the gain change of an erbium-doped fiber amplifier was successfully suppressed to 0.18 dB/sub pp/ in the temperature range between 0/spl deg/C and 65/spl deg/C and the wavelength range of 37.0 nm.

Single-mode 32-fiber connector with GI fiber lens array

A single-mode 32-fiber lensed connector has been developed. Insertion loss of 1.0 dB on average was achieved by MT connector based structure. Return loss of more than 30 dB was achieved by non-coaxial optical design.