National Institute of Advanced Industrial Science and Technology

Fujitsu Corporation

Keijiro Suzuki

Kazuhiro Ikeda

Hitoshi Kawashima

Ken Tanizawa

Suguru Akiyama

Takeshi Matsumoto

Shu Namiki

Hiroyuki Matsuura

Haruhiko Kuwatsuka

Satoshi Suda

Guangwei Cong

An optical amplifier includes a polarization splitter, a polarization rotator, first and second optical couplers, and first and second semiconductor optical amplifying devices. The TE polarized wave of light split by the polarization splitter is input to a first input port of the first optical coupler. The TM polarized wave of the split light is converted into a TE polarized wave by the polarization rotator to be input to a second input port of the first optical coupler. First light and second light output from a first output port and a second output port of the first optical coupler are amplified by the first semiconductor optical amplifying device and the second semiconductor optical amplifying device to be input to a first input port and a second input port of the second optical coupler, respectively. Third light is output from an output port of the second optical coupler.

Optical amplifier and optical switch device

Provided is a driving device for PWM control of voltage pulses for controlling the temperature of a heater in a phase controller, the driving device being capable of increasing the response speed of an optical element such as an optical switch. Phase controllers include first and second heaters for changing the temperatures of first and second optical waveguides extending in parallel. Driving devices include pulse generation circuits that generate voltage pulses to apply to the first and second heaters. To start raising the temperature of the second heater, the pulse generation circuit generates a first voltage pulse and consecutive second voltage pulses to apply to the second heater with zero voltage pulse being applied to the first heater, the first voltage pulse having a long pulse width and the second voltage pulses following the first voltage pulse and having a shorter pulse width than the first voltage pulse.

Driving device and driving method for phase controller, and optical switch

Growing community of inventors

Tsukuba, Japan

Keijiro Suzuki