A method of determining initial parameters and target values for tuning an emission wavelength of a wavelength tunable laser capable of emitting laser light in a substantial wavelength range is disclosed. The method iterates an evaluation of initial parameters and target values at target wavelengths in a preset order. The evaluation includes steps of supplying empirically obtained parameters to the t-LD, confirming whether the t-LD generates an optical beams, determining the initial parameters and the target values by carrying out feedback loops of the AFC and the APC when the t-LD generates the optical beam, or shifting the wavelength range so as to exclude the current target wavelength when the t-LD generates no optical beam.

An optical device is provided that includes an active waveguide having a top electrode and a plurality of layers including a gain layer. Configurations are disclosed for the active waveguide to enable amplification of a guided optical wave profile while preserving a shape of a lateral optical intensity profile of the guided optical wave as the guided optical wave is amplified along the waveguide. The top electrode and/or one or more layers of the active optical waveguide may be tailored to provide a tailored optical gain.

A laser-based light source includes a laser device configured to generate laser light of a predetermined laser wavelength and emit this laser light as a laser beam. A light-conversion device is configured to convert at least part of the laser light into converted light and a laser-output sensor is configured to determine a laser-output signal proportional to the output of laser light emitted by the laser device. Further, a converted-light sensor is configured to determine a converted-light signal proportional to the output of converted light emitted by the light-conversion device. A controller is configured to receive the laser-output signal and the converted-light signal, to determine a safe-to-operate parameter, based on the laser-output signal and the converted-light signal, and to control the operation of the laser-based light source based on a comparison of the safe-to-operate parameter with a at least one predefined threshold.

An apparatus, and related method, relates generally to a fiber-optic sensing system. In such a system, fiber-optic sensors are in a rosette or rosette-like pattern. An optical circulator is coupled to receive a light signal from a broadband light source, to provide the light signal to the fiber-optic sensors, and to receive a returned optical signal from the fiber-optic sensors. A spectral engine is coupled to the optical circulator to receive the returned optical signal and configured to provide an output signal.

In a laser light emitting device including a plurality of laser light emitter each including a laser diode, a drive circuit configured to drive the laser diode by controlling the supply of a drive current to the laser diode, and a drive line through which the drive current flows from the drive circuit to the laser diode, a light emission detector includes a detection pattern placed so as to cause an electromagnetically induced current to flow in response to a drive current flowing through each drive line when the corresponding laser light emitter emits light. The light emission detector detects light emission from a driven laser diode by detecting the current flowing in the detection pattern.

A laser apparatus includes: a laser unit including: a laser element unit including a phase adjusting portion configured to adjust an optical length of a laser resonator and enable frequency of laser light to be tuned; and a monitor unit configured to obtain a monitored value corresponding to the frequency of the laser light; a temperature controller configured to control temperature of the laser unit; and a control unit configured to execute: controlling the phase adjusting portion such that the monitored value is adjusted to a target monitored value corresponding to a target frequency set as the frequency of the laser light, while maintaining temperature set for the temperature controller constant; and controlling the temperature controller such that the frequency of the laser light is adjusted to the target frequency in a case where continuous fine adjustment control of the frequency of the laser light has been instructed.

A method of controlling an optical output power of a laser diode associated with a photodiode includes obtaining first optical trimming parameters indicative of a first optical output power of the laser diode at a first laser diode current and a second optical output power of the laser diode at a second laser diode current above lasing threshold. Next, second electrical trimming parameters indicative of a photodiode characteristic curve of photodiode current versus laser diode current are obtained. A first photodiode current and a second photodiode current at a laser diode currents below lasing threshold. A slope of a photodiode current versus laser diode current is determined. The optical output power of the laser diode above lasing threshold is controlled based on the first optical trimming parameters, the second electrical trimming parameters and the slope of the photodiode current versus laser diode current below lasing threshold.

A DC-coupled laser driver circuit with large modulation current belongs to the optical field. The present invention solves the problem that the conventional laser driver circuit consumes too much voltage margin because the transistor is used as the tail current source, resulting in a small modulation current. The present invention includes a negative feedback unit, an adaptive drive unit, a mirrored tail current source, a resistor R11, a resistor R12, a bias current source IBIAS and a diode D2; The resistor R12, laser D1, resistor R11, and bias current source IBIAS are connected in series between the voltage VCC and the ground in sequence; the input terminal of the negative feedback unit is connected to the data signal input ports TINP and TINN, the output terminal of the negative feedback unit is connected to the input terminal of the adaptive drive unit, the output terminal of the adaptive drive unit is connected to the control signal input terminal of the mirrored tail current source, a drive signal output terminal of the mirrored tail current source is connected to the anode of the laser D1 through a diode D2, the other drive signal output terminal of the mirrored tail current source is connected to the cathode of the laser D1.

A method and apparatus provide for determining a temperature at a junction of a laser diode when the laser diode is operated in a lasing state that facilitates heat-assisted magnetic recording, comparing the junction temperature and an injection current supplied during the lasing state to stored combinations of junction temperature and injection current, and determining a likelihood of mode hopping occurring for the laser diode during the lasing state based on the comparison to stored combinations of junction temperature and injection current.

An optoelectronic device includes a laser diode having a cathode terminal and an anode terminal, which is connected to a driving voltage. A driver is coupled to drive current pulses through the laser diode from the anode terminal to the cathode terminal. A discharge switch has a first switch terminal connected to the cathode terminal and a second switch terminal connected to a discharge voltage, which is equal to or greater than the driving voltage, and is configured, when closed, to raise the cathode terminal to the discharge voltage. A switch control circuit has an input connected to the cathode terminal and an output connected to close the discharge switch in response to the current pulses occurring at the input.