A narrow linewidth laser in which an all-optical feedback line-up is used to improve the linewidth from a conventional laser source, such as a laser diode. The feedback line-up comprises an optical device having a controllable unbalanced optical coupler arranged on a cavity input path to couple a source signal from the laser source into the optical cavity, and to couple a seed signal received back from the optical cavity into the laser source. The seed signal has a lower power than the source signal. The unbalanced optical coupler may be an optical isolator arranged to couple the seed signal into the laser source at a power level selected to promote preferential stimulated emission within a narrower linewidth. By controlling the power of seed signal such that only a small portion thereof influences the lasing cavity, the narrowing effect of the preferential stimulated emission can be enhanced.

An optical pump may include a polarization element to separate pump light into a first component beam and a second component beam, wherein the polarization element is to separate the pump light such that the first component beam has a first polarization and the second component beam has a second polarization that is different from the first polarization. The optical pump may include a gain medium to absorb a portion of the first component beam and a portion of the second component beam, and transmit an unabsorbed portion of the first component beam and an unabsorbed portion of the second component beam. The optical pump may include one or more optical elements to at least partially isolate a pump source from the unabsorbed portion of the first component beam and the unabsorbed portion of the second component beam.

A light isolator member of an embodiment of the present invention is configured to be joined to another light isolator member to serve as a part of a light isolator, the light isolator member including: a lens surface disposed in a first surface; a transmission surface disposed at a position corresponding to the lens surface in a second surface on a side opposite to the first surface; and a fitting part disposed in the second surface, the fitting part being configured for fitting to the other light isolator member.

An optical isolator for suppressing back reflections from a downstream optical system is described. The optical isolator includes a plurality of optical paths between a splitter and a combiner. One or more of the optical paths include two phase modulators that are driven by oscillating signals having predefined phase relationships. At least one bypass optical path does not include two phase modulators driven by oscillating signals. Amplitude and phase of an optical signal traversing the bypass optical path may be tuned to further suppress residual reflections from a downstream optical system.

A microfabricated optical apparatus that includes a light source driven by a waveform, a turning mirror, and a beam shaping element, wherein the waveform is delivered to the light source by at least one through silicon via. The microfabricated optical apparatus may also include a light-sensitive receiver which generates an electrical signal in response to an optical signal. The electrical signal may be communicated to external devices by at least one additional through silicon via.

A white light spectroscopy system includes a super continuum light source having an input light source including semiconductor diodes to generate an input beam having a wavelength shorter than 2.5 microns. The light source includes a cladding-pumped fiber optical amplifier to receive the input beam, and a photonic crystal fiber to receive the amplified optical beam to broaden the spectral width to 100 nm or more forming an output beam in the visible wavelength range. The output beam is pulsed with a repetition rate of 1 Megahertz or higher. The system also includes a lens and/or mirror to receive the output beam, to send the output beam to a scanning stage, and to deliver the received output beam to a sample. A detection system includes dispersive optics and narrow band filters followed by one or more detectors to permit approximately simultaneous measurement of at least two wavelengths from the sample.

In an embodiment, a laser apparatus comprises a semiconductor laser, e.g., of the VECSEL type, for generating pulsed laser radiation having a pulse duration in the femtosecond range or shorter and having a pulse repetition rate of at least 100 MHz; a selector for selecting groups of pulses from the laser radiation, each pulse group comprising a plurality of pulses at the pulse repetition rate, wherein the pulse groups are time-displaced by at least 500 ns; a scanner device for scanning a focal point of the laser radiation; a controller for controlling the scanner device based on a control program including instructions that, when executed by the controller, bring about the creation of a LIOB-based photodisruption for each pulse group in a target material, e.g. human eye tissue.

This optical receptacle comprises: a first optical surface through which light from a photoelectric conversion element is incident; a second optical surface through which the incident light is emitted to the optical transmitter side; an optical separation part which separates the incident light into monitor light that goes to a detection element and signal light that goes to the optical transmitter; and a third optical surface through which the monitor light is emitted to the detection element side. The securing part secures the optical transmitter such that the signal light from the second optical surface arrives at the end surface of the optical transmitter at a position farther than the focus of the second optical surface. The light flux diameter in the light separation part of the light incident through the second optical surface is smaller than the light flux diameter of the light in the second optical surface.

A compact and highly efficient coupling structure for coupling between DFB-LD and Si PIC edge coupler with suppressed return loss may include a DFB-LD, a Si PIC comprising at least one input edge coupler and at least one output edge coupler, a silica cover lid disposed on the Si PIC and aligned edge to edge with the Si PIC, a single-mode fiber aligned to the at least one output edge coupler of the Si PIC, a lens disposed between the DFB-LD and the at least one input edge coupler of the Si PIC, and an isolator bonded to a facet of the at least one input edge coupler with a first volume of an index matching fluid. The lens may be configured to minimize a mismatch between an output spot size of the DFB-LD and a spot size of the at least one input edge coupler of the Si PIC.

An optical device may include a semiconductor laser chip to independently generate four laser beams at different wavelengths. Each laser beam, of the four laser beams, may be directed to a respective optical output of the optical device with a sub-micron level of tolerance of each laser beam relative to the respective optical outputs of the optical device, and each laser beam, of the four laser beams, may be associated with a different optical path from the semiconductor laser chip to the respective optical output of the optical device. The optical device may include a lens to receive each of the four laser beams. The lens may be positioned to direct each laser beam, of the four laser beams, toward the respective optical output of the optical device. The optical device may include an optical isolator to receive each of the four laser beams.