Mitsubishi Electric Corporation

Mitsubishi Electric Research Laboratories, Inc.

Mitsubishi Denki Kabushiki Kaisha

Mitsunobu Gotoda

Toshiaki Koike-Akino

Keisuke Kojima

Masakazu Takabayashi

Eitaro Ishimura

Mohammad Tahersima

Kieran Parsons

Yoshihito Hirano

Koichi Akiyama

Tetsuya Nishimura

Chungwei Lin

Masao Imaki

Yuichiro Horiguchi

Min Teng

Muhammad Tahersima

A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n1, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n1, wherein the curved grating lines have line width w and height d and are arranged by a pitch &#x39b;, wherein the second refractive index n2 is less than first refractive index n1, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n3.

Integrated grating coupler

This variable wavelength laser device comprises a first semiconductor chip having first and second waveguides disposed in parallel, and a second semiconductor chip having an optical circuit optically connected to the first and second waveguides that, in conjunction with the first and second waveguides, constitute a resonator. Each of the first and second waveguides has two or more surface electrodes. The second semiconductor chip has a plurality of electrodes joined to the surface electrodes of the first and second waveguides.

Variable wavelength laser device and variable wavelength laser device production method

A grating coupler having first and second ends for coupling a light beam to a waveguide of a chip includes a substrate configured to receive the light beam from the first end and transmit the light beam through the second end, the substrate having a first refractive index n, a grating structure having curved grating lines arranged on the substrate, the grating structure having a second refractive index n, wherein the curved grating lines have line width w and height d and are arranged by a pitch &#x39b;, wherein the second refractive index nis less than first refractive index n, and a cladding layer configured to cover the grating structure, wherein the cladding layer has a third refractive index n

Integrated grating coupler system

Grating coupler and integrated grating coupler system

An optical ring circuit for modulating light from a light source into an optical signal includes a ring modulator located near a waveguide to couple a light propagating the waveguide, the ring modulator including a pair of electrodes, a signal generator to transmit an electrical signal corresponding to the optical signal, a filter circuit to generate an output signal, wherein the filter circuit includes an adder unit and at least one tap unit having a delay unit and a coefficient unit, wherein the adder unit adds the electrical signal from the signal generator and a signal passed from the tap unit for pre-compensating signal components of the electrical signal by at least twice delay time of the delay unit, and a driver circuit to apply a voltage to the electrodes based on the output signal.

Optical ring circuit with electrical filter

A semiconductor laser according to the present invention includes an active layer, a guide layer laminated on the active layer, a diffraction grating formed along a light emission direction in the guide layer, an upper electrode provided above the guide layer, and a lower electrode provided below the active layer. The diffraction grating includes a current-injection diffraction grating and current-non-injection diffraction gratings provided both in front of and in back of the current-injection diffraction grating. Phase shifters are individually provided at a central portion of the current-injection diffraction grating and at boundaries between the current-injection diffraction grating and the current-non-injection diffraction gratings. The upper electrode is provided above the current-injection diffraction grating and is not provided above the current-non-injection diffraction gratings.

Semiconductor laser and optical integrated light source including the same

A first arm portion and a second arm portion are provided so as to have a distance therebetween greater than a distance between input ends of two output waveguides and greater than a distance between an output end of a first output portion and an output end of a second output portion, the first arm portion forming a traveling path of light from one of the two output waveguides to the first output portion through a first optical amplifier, the second arm portion forming a traveling path of light from another one of the two output waveguides to the second output portion through a second optical amplifier. The first optical amplifier and the second optical amplifier have curved portions in which the first output portion and the second output portion are curved in a direction toward each other, and the first optical amplifier and the second optical amplifier respectively output light from the output end of the first output portion and the output end of the second output portion.

Wavelength-tunable light source and wavelength-tunable light source module

A wavelength variable light source according to the present invention includes: an MMI that includes an input side and an output side, the input side connecting to one end of each of a plurality of MMI input waveguides, and the output side connecting to a plurality of MMI output waveguides, the MMI multiplexing light input from each of the MMI input waveguides and outputting the multiplexed light to each of the MMI output waveguides; a plurality of DFB-LDs connected to the other end of each of the MMI input waveguides, each of the MMI output waveguides performing a single mode oscillation at a different wavelength; and two SOAs respectively connected to two MMI output waveguides of the MMI output waveguides, and having different gains from each other.

Wavelength variable light source and wavelength variable light source module

An oscillation state of a semiconductor laser is decided. Injection current to the first and second light reflectors of the semiconductor laser are simultaneously swept based on the oscillation state of the semiconductor laser to obtain current conditions of the injection current to the first and second light reflectors that carry out single-mode oscillation in a target wavelength. The semiconductor laser is drive controlled with the obtained current conditions.

Method of and apparatus for controlling wavelength variable semiconductor laser without preparing a high-precision current table

A wavelength-tunable semiconductor laser includes a semiconductor substrate; an optical waveguide on an upper surface of the semiconductor substrate; a front light reflection area including an SG-DBR mirror with repeating pairs of a diffraction grating portion and a non-diffraction grating portion over plural periods; a rear light reflection area including an SSG-DBR mirror achieved with repeating portions in which the pitch of a diffraction grating pitch regularly varies from one end to the other end; an active region including an active layer between the front light reflection area and the rear light reflection area; and a phase control area between the front light reflection area and the rear light reflection area and including a phase control layer with a refractive index varied by current injection.

Variable wavelength semiconductor laser and optical module

A high performance single-wavelength semiconductor laser device having stable and high-speed operation includes an active region, a forward light reflection region located in front of the active region, a backward light reflection region located behind the active region, and a phase control region located in proximity to the active layer, all sandwiched between an upper cladding layer and a lower cladding layer. The forward light reflection region and the backward light reflection region include alternate diffraction grating portions and non-diffracting portions alternately. The laser oscillates at a wavelength which corresponds to the current flowing in the diffraction grating portion. A current blocking layer is located on the non-diffracting portion of at least one of the forward light reflection region and the backward light reflection region for blocking current from flowing into the non-diffracting portion.

Growing community of inventors

Tokyo, Japan

Mitsunobu Gotoda