Sumitomo Electric Industries, Limited

National Institute of Advanced Industrial Science and Technology

Hajime Shoji

Katsumi Uesaka

Eiichi Banno

Shu Namiki

Ken Tanizawa

Hiroyuki Matsuura

Haruhiko Kuwatsuka

Hideki Yagi

Naoki Fujiwara

Takehiko Kikuchi

Takuo Hiratani

Toshiyuki Nitta

A semiconductor optical device includes an SOI substrate having a waveguide of silicon, and at least one gain region of a group III-V compound semiconductor having an optical gain bonded to the SOI substrate. The waveguide has a bent portion and multiple linear portions extending linearly and connected to each other through the bent portion. The gain region is disposed on each of the multiple linear portions.

Semiconductor optical device

A laser apparatus for tuning the emission wavelength of a wavelength tunable laser diode will be described. The apparatus includes a tunable LD with heaters to tune the emission wavelength of the tunable LD, and a controller to control the power supplied to the heaters. A feature of the laser apparatus is that the controller supplies pre-emphasis power to the heaters before the supplement of the power corresponding to the re-tuned emission wavelength to accelerate the stability of the temperature of the heaters.

Laser apparatus and method to re-tune emission wavelength tunable LD

A system includes: a splitter to branch an optical signal output by a wavelength-tunable light source into first to third optical signals; a first photodiode to perform an optical electrical conversion of the first optical signal transmitting a first etalon; a second photodiode to perform an optical electrical conversion of the second optical signal transmitting a second etalon, an FSR of the second etalon being identical to that of the first etalon, peak wavelengths of intensity of a transmitted light of the second etalon being different from those of the first etalon; a third photodiode to perform an optical electrical conversion of the third optical signal; and a controller to control the wavelength-tunable light source with use of a coefficient calculated by following formulas (1) or (2), Coefficient=(PD1&#x2212;A&#xb7;PD3)/(PD2&#x2212;B&#xb7;PD3) (1) and Coefficient=(PD2&#x2212;B&#xb7;PD3)/(PD1&#x2212;A&#xb7;PD3) (2).

System to control wavelength and method to control wavelength

Growing community of inventors

Yokohama, Japan

Hajime Shoji