An exposure system according to an aspect of the present disclosure includes a laser apparatus that outputs pulsed laser light, an illuminating optical system that guides the pulsed laser light to a reticle, a reticle stage, and a processor that controls the output of the pulsed laser light from the laser apparatus and the movement of the reticle performed by the reticle stage. The reticle has a first region where a first pattern is disposed and a second region where a second pattern is disposed, and the first and second regions are each a region continuous in a scan width direction perpendicular to a scan direction of the pulsed laser light, with the first and second regions arranged side by side in the scan direction. The processor controls the laser apparatus to output the pulsed laser light according to each of the first and second regions by changing the values of control parameters of the pulsed laser light in accordance with each of the first and second regions.

Systems and methods here may include improved tunable lasers having a tunable filter and a tunable channel selector that can control precisely the wavelength and the bandwidth of the light emitted by the laser, while suppressing light that may otherwise be emitted by the laser outside the desired wavelength and bandwidth with unidirectional ring lasers having a resonator of which forms a ring and where light propagates only in one of the two possible directions.

A Lidar system includes a tunable laser configured to generate an output light signal and a photodiode array for receiving light from the tunable laser reflected from a target object. The tunable laser includes a feedback loop including a Mach-Zender interferometer, MZI, receiving the output light signal from the tunable laser, in which the MZI includes two optical paths receiving the output light signal. A phase shifter is provided in one optical path that is operable to produce a pre-determined shift in the phase angle of the light signal passing through the one optical path relative to the phase angle of the light signal passing through the other optical path. A photodiode configured to detect the interference signal generated by the MZI is operable to generate a photodiode current in response thereto. Circuitry converts the photodiode current to a control signal for controlling the tunable laser.

A control system for frequency control of a laser module, comprising at least one laser module for generating laser radiation, at least one control device coupled or configured to couple to the laser module, and at least one optical resonator coupled or configured to couple to the control device, wherein the control device comprises a semiconductor substrate, a first Pound-Drever-Hall system arranged on the semiconductor substrate and at least one second Pound-Drever-Hall system arranged on the semiconductor substrate, wherein the laser module is coupled to the first Pound-Drever-Hall system of the control device and is configured to couple to the at least second Pound-Drever-Hall system of the control device, wherein the first Pound-Drever-Hall system is coupled to the optical resonator and wherein the second Pound-Drever-Hall system is configured to couple to the optical resonator, and wherein the number of Pound-Drever-Hall systems is greater than the number of laser modules or optical resonators.

A control system for frequency control of a laser module, comprising at least one laser module for generating laser radiation, at least one control device coupled or configured to couple to the laser module, and at least one optical resonator coupled or configured to couple to the control device, wherein the control device comprises a semiconductor substrate, a first Pound-Drever-Hall system arranged on the semiconductor substrate and at least one second Pound-Drever-Hall system arranged on the semiconductor substrate, wherein the laser module is coupled to the first Pound-Drever-Hall system of the control device and is configured to couple to the at least second Pound-Drever-Hall system of the control device, wherein the first Pound-Drever-Hall system is coupled to the optical resonator and wherein the second Pound-Drever-Hall system is configured to couple to the optical resonator, and wherein the number of Pound-Drever-Hall systems is greater than the number of laser modules or optical resonators.

Coupled-cavity vertical cavity surface emitting lasers (VCSELs) are provided by the present disclosure. The coupled-cavity VCSEL can comprise a VCSEL having a first mirror, a gain medium disposed above the first mirror, and a second mirror disposed above the gain medium, wherein a first cavity is formed by the first mirror and the second mirror. A second cavity is optically coupled to the VCSEL and configured to reflect light emitted from the VCSEL back into the first cavity of the VCSEL. In some embodiments, the second cavity can be an external cavity optically coupled to the VCSEL through a coupling component. In some embodiments, the second cavity can be integrated with the VCSEL to form a monolithic coupled-cavity VCSEL. A feedback circuit can control operation of the coupled-cavity VCSEL so the output comprises a target high frequency signal.

Coupled-cavity vertical cavity surface emitting lasers (VCSELs) are provided by the present disclosure. The coupled-cavity VCSEL can comprise a VCSEL having a first mirror, a gain medium disposed above the first mirror, and a second mirror disposed above the gain medium, wherein a first cavity is formed by the first mirror and the second mirror. A second cavity is optically coupled to the VCSEL and configured to reflect light emitted from the VCSEL back into the first cavity of the VCSEL. In some embodiments, the second cavity can be an external cavity optically coupled to the VCSEL through a coupling component. In some embodiments, the second cavity can be integrated with the VCSEL to form a monolithic coupled-cavity VCSEL. A feedback circuit can control operation of the coupled-cavity VCSEL so the output comprises a target high frequency signal.

A laser system includes a resonant laser cavity configured to output a laser signal. The system also includes a utility waveguide configured to receive the laser signal from the laser cavity. The utility waveguide includes a perturbation region that is external to the laser cavity and receives the laser signal from the laser cavity and outputs a laser beam. The perturbation region includes one or more perturbation structures that each causes one or more perturbation(s) in the index of refraction of the utility waveguide. The perturbation structures are selected to provide optical feedback to the resonant laser cavity such that a power versus wavelength distribution in the laser beam is different from the power versus wavelength distribution that would be in the laser signal in the absence of the perturbation structures.

A thin-film device for a wavelength-tunable semiconductor laser. The device includes a cavity between a high-reflectivity facet and an anti-reflection facet designed to emit a laser light of a wavelength in a tunable range determined by two Vernier-ring resonators with a joint-free-spectral-range between a first wavelength and a second wavelength. The device further includes a film including multiple pairs of a first layer and a second layer sequentially stacking to an outer side of the high-reflectivity facet. Each layer in each pair has one unit of respective optical thickness except one first or second layer in one pair having a larger optical thickness. The film is configured to produce inner reflectivity of the laser light from the high-reflectivity facet at least >90% for wavelengths in the tunable range starting from the first wavelength but at least <50% for wavelengths in a 25 nm range around the second wavelength.

To provide a light source device for a fiber optic gyroscope capable of broadening the bandwidth of the laser light and improving stability of a scale factor.

A light source device for a fiber optic gyroscope configured to drive a fiber optic gyroscope includes: a laser light source 10, a stabilizing part 20, and a bandwidth broadening part 30. The laser light source 10 emits a laser light of a predetermined frequency. The stabilizing part 20 stabilizes the predetermined frequency of the laser light emitted from the laser light source 10. The bandwidth broadening part 30 makes the laser light stabilized by the stabilizing part 20 into a light having a continuous broadband spectrum.