Narrow-optical linewidth laser generation devices and methods for generating a narrow-optical linewidth laser beam are provided. One narrow-optical linewidth laser generation devie includes a single-wavelength mirror or multiwavelength mirror (for comb lasers) formed from one or more optical ring resonators coupled with an optical splitter. The optical splitter may in turn be coupled with a quantum dot optical amplifier (QDOA), itself coupled with a phase-tuner. The phase tuner may be further coupled with a broadband mirror. The narrow-optical linewidth laser beam is generated by using a long laser cavity and additionally by using an integrated optical feedback.

An improvement is made to a non-Raman spectroscopy method and apparatus in which a quantum entangled transmission package formed in a quantum well in a laser is directed to a target and in which the apparatus receives emission packages from the target. A control circuit triggers the laser to emit a laser beam. The transmission package is sent via the laser beam by an emission fiber and the emission package is received by a collection fiber. The collection fiber and the transmission fiber may be included in a Raman probe. The collection fiber provides an input to a monochromator comprising a diffraction grating. The diffraction grating is constructed to permit selection of any of a wide range of wavelengths. A spectrometer receives an output from the diffraction grating. The spectrometer output is measured by a photomultiplier to provide an input to the control module. A number of different spectra are selectively generated. Also, the transmission package may be formed with a power level to affect structure of a preselected target.

In a device for generating output laser pulses having a tunable central wavelength, based on parametric amplification, a laser system is to be provided that has less complexity, but that nevertheless provides great tunability for the wavelength, permits rapid switching of the wavelength, and allows the spectral bandwidth of the emitted pulses to be adjusted. This is attained in that for adjustability of the bandwidth of the output laser pulses, an optical device is provided that is designed to influence the spectral phase of the pump pulses as a function of the spectral phase of the seed pulses.

In a first embodiment, an external cavity tunable laser, comprising a silicon photonics circuit comprising one or more resonators having one or more p-i-n junctions; wherein a voltage is applied to one or more of the p-i-n junctions. In a second embodiment, a method of operating an external cavity tunable laser, comprising sweeping out free-carriers from a resonator of the tunable laser by applying a voltage to a p-i-n junction of a waveguide of the resonator.

An optical transmitter and a method for driving the optical transmitter include emitting an optical signal using a laser having a lasing cavity with a first section and a second section, performing, using a first heater thermally coupled to the first section, a first temperature control on the first section using a first control signal, and performing, using a second heater thermally coupled to the second section, a second temperature control on the second section using a second control signal. The first temperature control is independent from the second temperature control.

A system for continuously phase tuning an optical signal includes one optical switch coupled to a phase modulator having a first waveguide with a first phase shifter and a second waveguide with a second phase shifter. The optical switch alternately switches between the first and second phase shifters to phase shift the optical signal, respectively. The continuously phase tuning system further includes a loop mirror that alternately receives the phase shifted optical signal from the first and second waveguides in accordance with the switching, via corresponding first and second mirror inputs, respectively, and reflects the phase shifted optical signal back to the same first or second mirror input at which the phase shifted optical signal was received. First and second phase values of the first and second phase shifters are determined such that overall phase change continues to accumulate substantially linearly.

In a device for generating output laser pulses having a tunable central wavelength, based on parametric amplification, a laser system is to be provided that has less complexity, but that nevertheless provides great tunability for the wavelength, permits rapid switching of the wavelength, and allows the spectral bandwidth of the emitted pulses to be adjusted. This is attained in that for adjustability of the bandwidth of the output laser pulses, an optical device is provided that is designed to influence the spectral phase of the pump pulses as a function of the spectral phase of the seed pulses.

A reflection filter device includes: a ring resonator filter including a ring-shaped waveguide and two arms, each of the two arms being optically coupled to the ring-shaped waveguide; and a dual-branch portion including a light input/output port and two branch ports, the light input/output port being configured to allow input and output of light, the two branch ports being configured to allow output of the light input from the light input/output port, the light being split into two, the two arms being connected to the two branch ports, respectively, at least one of the two arms being equipped with a phase adjuster.

A waveguide based wavelength-tunable laser formed on a semiconductor substrate includes a first reflector from which laser light is output, a second reflector configuring a laser resonator together with the first reflector, a gain portion that is provided between the first reflector and the second reflector, at least two wavelength filters that can adjust wavelength characteristics and adjust a wavelength of the laser light, and a phase adjuster that adjusts an optical path length in the laser resonator, and a waveguide is formed to fold back an optical path by an angle of substantially 180 degrees between the first reflector and the second reflector.

A method of operating an optoelectronic device comprising an optical waveguide section, the optical waveguide section comprising a semiconductor core, the method comprising the steps of determining (401) a range for a negative bias voltage for the waveguide section for which an optical loss of the core is lower than an optical loss at zero bias for an operating wavelength range of the device, selecting (402) a bias voltage within the range and applying (403) the selected bias voltage to the waveguide section.