Abstract: The present invention concerns a method for controlling the emitting wavelength of a laser source (10) for a passive optical network, the laser source (10) comprising: a first Bragg mirror (12), a second Bragg mirror (14), a cavity (16) delimited by both Bragg mirrors (12, 14), the cavity (16) comprising an optical filter (18) and an active medium (20), the method comprising the steps of: measuring the temperature of the active medium (20), setting the temperature of the optical filter (18) in accordance with the measured temperature of the active medium (20), the temperature of the optical filter (18) being higher than the measured temperature.

Abstract: An integrated optical structure includes at least one optical isolator, having a magneto-optical layer, associated with at least one SOA optical amplifier having a waveguide having an n-doped semiconductor layer, a p-doped semiconductor layer, and an active area disposed between the n-doped semiconductor layer and the p-doped semiconductor layer. The optical isolator is disposed between an SOI base and the SOA optical amplifier's waveguide. The optical isolator's magneto-optical layer is disposed between a lower insulating layer and an upper insulating layer. The optical isolator's magneto-optical layer may be a layer of ferromagnetic metallic material, such as a Fe—Co metallic alloy, or a magnetic oxide layer. An optical device includes at least one integrated optical structure.

Abstract: In the field of narrow linewidth laser sources and a laser device that comprises a laser source and a waveguide of determined refractive index with which it is coupled, a waveguide is single-mode and includes at least four reflectors in the form of trenches etched into the waveguide and irregularly distributed along the waveguide, the distance separating two neighbouring reflectors being above 1 pm, and the waveguide and the laser source have respective lengths such that the length of waveguide over which the reflectors are located is greater than the length of the laser source itself.

Abstract: A camera module includes an image sensor, a circuit board, and a stiffener. The stiffener is located one side of the circuit board and includes a bottom plate grounded. The image sensor is located on another side of the circuit board. The stiffener includes a sidewall extending from the bottom plate. The sidewall and the bottom plate cooperatively hold the circuit board. An insulative coating is coated on the sidewall to avoid short circuiting.

Abstract: A wavelength tunable laser emission device (1) comprises: a first waveguide (31) comprising an optical amplification means for producing a stimulated light emission, the first waveguide extending in a longitudinal direction of the emission device, a second waveguide (5) made of silicon on silicon dioxide and disposed parallel to the first waveguide spaced from the first waveguide in a vertical direction of the emission device so as to allow the existence of a hybrid optical mode coupled at one and the same time to the second waveguide and to the first waveguide, the second waveguide comprising a distributed reflector (9) along the second waveguide, the second waveguide comprising transverse zones (11, 12, 13, 14) doped differently so as to form a polar junction oriented in a transverse direction of the emission device. Electrodes (15, 16) coupled to the doped transverse zones modify an effective index seen by the hybrid optical mode.

Abstract: An integrated optical structure includes at least one optical isolator, having a magneto-optical layer, associated with at least one SOA optical amplifier having a waveguide having an n-doped semiconductor layer, a p-doped semiconductor layer, and an active area disposed between the n-doped semiconductor layer and the p-doped semiconductor layer. The optical isolator is disposed between an SOI base and the SOA optical amplifier's waveguide. The optical isolator's magneto-optical layer is disposed between a lower insulating layer and an upper insulating layer. The optical isolator's magneto-optical layer may be a layer of ferromagnetic metallic material, such as a Fe—Co metallic alloy, or a magnetic oxide layer. An optical device includes at least one integrated optical structure.

Abstract: A coupler/splitter including two neighboring coplanar waveguide portions extending in a same direction, the first portion having a constant cross-section, the second portion having a variable cross-section so that the effective index of the second waveguide portion varies, in the upstream-to-downstream direction, from a first lower value to a second value higher than the effective index of the first portion, in adiabatic coupling conditions.

Abstract: An photonic device, comprising one section of a material which is different from the material of another section such that the two sections present different optical birefringent index values. This causes a first set of polarization modes to move in a spectral space with a different velocity than a second set of polarization modes. A bias current, or voltage, is used for controlling the overall birefringence effect in the device. The biasing for controlling the birefringence effect is performed such the TE modes and the TM modes of the device are made to coincide in their respective spectral position. Thus the device is made insensitive, or presents substantially reduced sensitivity, to the polarization of any incoming optical signal.

Abstract: In a process for fabrication of an optical slot waveguide on silicon, a thin single-crystal silicon film is deposited on a substrate covered with an insulating buried layer; a local thermal oxidation is carried out over the entire depth of the thin single-crystal silicon film in order to form an insulating oxidized strip extending along the desired path of the waveguide; an insulating or semi-insulating layer is deposited on the silicon film; two openings having vertical sidewalls are excavated over the entire thickness of this insulating or semi-insulating layer, said openings being separated by a narrow gap constituting an insulating or semi-insulating vertical wall that will be the material of the slot; single-crystal silicon is grown in the openings and right to the edges of the insulating or semi-insulating wall; and then the upper part of the silicon is etched in order to complete the geometry of the waveguide.

Abstract: In a process for fabrication of an optical slot waveguide on silicon, a thin single-crystal silicon film is deposited on a substrate covered with an insulating buried layer; a local thermal oxidation is carried out over the entire depth of the thin single-crystal silicon film in order to form an insulating oxidized strip extending along the desired path of the waveguide; an insulating or semi-insulating layer is deposited on the silicon film; two openings having vertical sidewalls are excavated over the entire thickness of this insulating or semi-insulating layer, said openings being separated by a narrow gap constituting an insulating or semi-insulating vertical wall that will be the material of the slot; single-crystal silicon is grown in the openings and right to the edges of the insulating or semi-insulating wall; and then the upper part of the silicon is etched in order to complete the geometry of the waveguide.

Abstract: An photonic device, comprising one section of a material which is different from the material of another section such that the two sections present different optical birefringent index values. This causes a first set of polarization modes to move in a spectral space with a different velocity than a second set of polarization modes. A bias current, or voltage, is used for controlling the overall birefringence effect in the device. The biasing for controlling the birefringence effect is performed such the TE modes and the TM modes of the device are made to coincide in their respective spectral position. Thus the device is made insensitive, or presents substantially reduced sensitivity, to the polarization of any incoming optical signal.

Abstract: An photonic device, comprising one section of a material which is different from the material of another section such that the two sections present different optical birefringent index values. This causes a first set of polarization modes to move in a spectral space with a different velocity than a second set of polarization modes. A bias current, or voltage, is used for controlling the overall birefringence effect in the device. The biasing for controlling the birefringence effect is performed such the TE modes and the TM modes of the device are made to coincide in their respective spectral position. Thus the device is made insensitive, or presents substantially reduced sensitivity, to the polarization of any incoming optical signal.

Abstract: A short circuit protection circuit for a pulse width modulation (PWM) unit which includes a PWM logic control circuit, an under voltage lookout (UVLO) circuit and an internal clock circuit; wherein the UVLO circuit detecting a bias power (Vcc) and delivering an UVLO signal when the bias power is judged excessively low, the PWM unit further comprising: a short circuit detector, a short circuit recovery circuit and a frequency multiplexer. The short circuit detector is to detect the UVLO signal and generate a short signal. The short circuit recovery circuit to set a pre-determined recovery time and generate a recovery signal when the pre-determined recovery time ends. The frequency multiplexer which is triggered by the short signal when the short circuit event occurs to change a switching frequency to a short PWM frequency, and triggered by the recovery signal to restore the switching frequency.

Abstract: A power adapter with voltage-stabilized compensation includes a pulse frequency modulation circuit to generate a driving pulse which has a variable OFF time interval to control power transformed and output by a transformer. The power adapter also has an ancillary coil to induce a feedback signal on the secondary coil of the transformer. The pulse frequency modulation circuit includes a time interval modulation unit to receive the feedback signal and a feedback compensation unit. The time interval modulation unit sets a level voltage compared with the feedback signal to generate a sample signal to modulate the OFF time interval. The feedback compensation unit provides a compensation signal to the time interval modulation unit to change the size of the feedback signal or sample signal thereby to compensate the voltage output from the secondary side.

Abstract: A power adapter with voltage-stabilized compensation includes a pulse frequency modulation circuit to generate a driving pulse which has a variable OFF time interval to control power transformed and output by a transformer. The power adapter also has an ancillary coil to induce a feedback signal on the secondary coil of the transformer. The pulse frequency modulation circuit includes a time interval modulation unit to receive the feedback signal and a feedback compensation unit. The time interval modulation unit sets a level voltage compared with the feedback signal to generate a sample signal to modulate the OFF time interval. The feedback compensation unit provides a compensation signal to the time interval modulation unit to change the size of the feedback signal or sample signal thereby to compensate the voltage output from the secondary side.

Abstract: A short circuit protection circuit for a pulse width modulation (PWM) unit which includes a PWM logic control circuit, an under voltage lookout (UVLO) circuit and an internal clock circuit; wherein the UVLO circuit detecting a bias power (Vcc) and delivering an UVLO signal when the bias power is judged excessively low, the PWM unit further comprising: a short circuit detector, a short circuit recovery circuit and a frequency multiplexer. The short circuit detector is to detect the UVLO signal and generate a short signal. The short circuit recovery circuit to set a pre-determined recovery time and generate a recovery signal when the pre-determined recovery time ends. The frequency multiplexer which is triggered by the short signal when the short circuit event occurs to change a switching frequency to a short PWM frequency, and triggered by the recovery signal to restore the switching frequency.

Abstract: An photonic device, comprising one section of a material which is different from the material of another section such that the two sections present different optical birefringent index values. This causes a first set of polarization modes to move in a spectral space with a different velocity than a second set of polarization modes. A bias current, or voltage, is used for controlling the overall birefringence effect in the device. The biasing for controlling the birefringence effect is performed such the TE modes and the TM modes of the device are made to coincide in their respective spectral position. Thus the device is made insensitive, or presents substantially reduced sensitivity, to the polarization of any incoming optical signal.

Abstract: A stabilised gain semiconductor optical amplifier (CG-SOA) includes and active waveguide (1) comprising an amplification medium (2), extending in longitudinal (Z), lateral (X) and vertical (Y) directions, and coupled to a laser oscillation structure comprising at least two resonant cavities (13, 14) extending in first (D1) and second (D2) directions which are different from the longitudinal direction (Z) of the active waveguide (1) and arranged in such a way as to permit the establishment of laser oscillations having at least two different relaxation oscillation frequencies.

Abstract: The field of the invention is that of the semiconductor optical devices used in particular for fibre-optic telecommunications. To function efficiently, a certain number of semiconductor devices require the use of light polarized in a given polarization state. When knowledge of the polarization the state is lost, the optical element according to the invention makes it possible to polarize the light again in a known polarization state. By using two of these elements in combination with a coupler, it is possible to produce a device which fulfils the same function as a polarization splitter. This optical assembly delivers two output signals whose polarization states are the projections of the initial polarization onto two orthogonal axes. The main advantage of these devices is that they are produced using polarization rotators based on photonic crystals, and they can consequently be integrated easily into semiconductor devices, which the use of discrete polarizers does not allow.

Abstract: The field of the invention is that of the semiconductor optical devices used in particular for fibre-optic telecommunications. To function efficiently, a certain number of semiconductor devices require the use of light polarized in a given polarization state. When knowledge of the polarization the state is lost, the optical element according to the invention makes it possible to polarize the light again in a known polarization state. By using two of these elements in combination with a coupler, it is possible to produce a device which fulfils the same function as a polarization splitter. This optical assembly delivers two output signals whose polarization states are the projections of the initial polarization onto two orthogonal axes. The main advantage of these devices is that they are produced using polarization rotators based on photonic crystals, and they can consequently be integrated easily into semiconductor devices, which the use of discrete polarizers does not allow.