National Institute of Advanced Industrial Science and Technology

Sumitomo Electric Industries, Limited

Hitachi Chemical Company, Ltd.

Hiroyuki Matsuura

Shu Namiki

Ken Tanizawa

Haruhiko Kuwatsuka

Katsumi Uesaka

Eiichi Banno

Hajime Shoji

Nobuo Miyadera

Kazuhiro Ikeda

Masatoshi Yamaguchi

Hitoshi Kawashima

Kiyoshi Yamanoi

Satoshi Suda

Keijiro Suzuki

Guangwei Cong

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

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

The present invention relates to an electrode structure, which comprises a substrate provided with an electrode formed thereon, wherein the substrate comprises a layer of a fluorine-containing polyimide and a layer of a fluorine-free resin is interposed between the polyimide layer and the electrode and, in particular, to the foregoing electrode structure, wherein the electrode comprises a gold layer as the outermost or surface layer and an aluminum layer interposed between the substrate and the gold layer. The electrode structure of the present invention never causes any peeling off of the electrode due to insufficient adhesion of the electrode to the substrate, the structure has sufficiently high strength and therefore the boundary between the substrate and the electrode formed thereon is not destroyed by the energy of ultrasonics applied thereto.

Electrode structure

Growing community of inventors

Tsukuba, Japan

Hiroyuki Matsuura