71 results about "Cavity loss" patented technology

A ring-cavity, passively mode locked fiber laser capable of producing short-pulse-width optical pulses at a relatively low repetition rate. The fiber laser uses a one-way ring-cavity geometry with a chirped fiber Bragg grating (CFBG) at its reflecting member. The CFBG is part of a dispersion compensator that includes an optical circulator that defines a one-way optical path through the ring cavity. A doped optical fiber section is arranged in the optical path and serves as the gain medium. A pump light source provides the pump light to excite the dopants and cause the gain medium to lase. A saturable absorber is operable to effectuate passive mode-locking of the multiple modes supported by the ring cavity. The ring cavity geometry allows to achieve mode locking with single pulse operation in a longer cavity length than conventional linear cavities. Furthermore, the longer cavity length reduces the constraints on the chirp rate of the CFBG. This, in turn, allows the CFBG to have a relatively high reflectivity, which provides the necessary dispersion compensation and cavity loss for generating short optical pulses at a low repetition rate.

Cavity enhanced absorption spectroscopy systems and methods for detecting trace gases. When the frequency of laser light approaches the frequency of a resonance cavity mode, the laser begins to fill the cavity to that mode. Optical intensity inside the cavity reflects total cavity loss when the laser light frequency coincides with the cavity mode transmission peak. The intra-cavity optical power also depends on the coupling efficiency of the laser beam to the particular cavity mode. Measurement of intensities of three optical signals, namely, intensity of the light incident on to the cavity, intensity of the light reflected from the cavity, and intensity of the intra-cavity optical power, with their appropriate normalization advantageously significantly reduce effects of baseline calibration and drift as the normalized signal only depends on total cavity loss, and not the coupling efficiency, as in traditional approaches.

A simultaneously super pulsed Q-switched CO2 laser system for material processing comprises sealed-off folded waveguides with folded mirrors that are thin film coated to select the output wavelength of the laser. The system also comprises a plurality of reflective devices defining a cavity; a gain medium positioned within the cavity for generating a laser beam; a cavity loss modulator for modulating the laser beam, generating thereby one or more laser pulses; a pulsed signal generation system connected to the cavity loss modulator for delivering pulsed signals to the cavity loss modulator thereby controlling the state of optical loss within the cavity; a control unit connected to the pulsed signal generation system for controlling the pulsed signal generation system; and a pulse clipping circuit receptive of a portion of the laser beam and connected to the pulsed signal generation system for truncating a part of the laser pulses.

An apparatus and method for use with a coherent optical source to detect environmental changes. The apparatus comprises: an optical cavity, including an input coupling port, and an optical fiber section; a detector optically coupled to the optical cavity to monitor radiation in the optical cavity; and a processor electrically coupled to the detector for analyzing the environmental changes adjacent the detection portion of the optical cavity based on a rate of decay of the radiation in the optical cavity monitored by the detector. The optical fiber section of the optical cavity includes a detection portion coated with a conductive layer capable of supporting a surface plasmon to provide cavity loss. The surface plasmon is responsive to the environmental changes adjacent the detection portion. The coherent optical source is optically coupled to the input coupling port of the optical cavity to provide the radiation in the optical cavity.

A spherical laser includes a transparent or semi-transparent outer spherical vessel having an internal cavity, an amplifying medium in the cavity, and means to excite the amplifying medium. The sphere is provided with a partially reflective coating to act as a spherical optical resonator. Excitation of the amplifying medium produces an optical gain. When the gain exceeds cavity losses and threshold conditions are met, lasing is supported. This creates a three-dimensional, spherically radiating emission, emulating a point source. The output is radially diverging, but is harnessed by enclosing the sphere within a mirrored ellipse to image the output to a point, or within a mirrored parabola to columinate the emission. A concentric, reflective inner sphere may be disposed in the cavity, with the amplifying medium lying between the two spheres. A voltage potential is applied between the spheres to excite the medium.

A method for expanding the output linewidth of the laser, used in the technical field of the laser display, includes the following steps: introducing a loss element changing along the wavelength of the laser gain area in the laser cavity, overlapping and compounding the loss curve and the laser medium gain curve in the laser cavity, to cause the laser gain central area with larger cavity loss in the laser cavity, thereby causing the laser wavelength with lower gain in the laser gain bandwidth to obtain the chance of the oscillation starting, consequently widening the output bandwidth of the whole laser. The method of the invention is not only used in the semiconductor pumping intracavity frequency double laser and the fundamental wave output laser in the embodiment, but also is used in the RGB laser of the laser display, which effectively restrains the speckle effect. In addition, the laser has small volume and low cost.

The invention relates to a self-cooling laser optical tweezers device and method based on a two-dimensional light trap. The light tweezers is combined to a light cavity, and the high-speed self-cooling for capturing ellipsoid particles is realized by utilizing the ellipsoid particles location and the characteristics of the cavity loss; the whole cooling process does not involve to the external feedback control, and is realized through the internal self-feedback of a ring cavity. The device has the advantages of being simple in structure, good in repeatability and strong in practicability. Furthermore, the self-cooling laser optical tweezers device is not limited to the light trap structure and the light path structure, and the applicable range is extremely wide.

The invention belongs to a method for measuring the loss parameter of a laser gyro, and relates to a method for measuring the diffraction loss of the laser gyro. The measurement method comprises the following steps: assembling a matched reflector to an unapertured cavity, starting a frequency sweep laser, adjusting a light path matching part to make laser enter a resonant cavity composed of an unapertured diaphragm and the reflector, and measuring the initial cavity loss L1 of the unapertured diaphragm resonant cavity through a loss measurement system; disassembling the matched reflector from the unapertured resonant cavity [5], assembling the matched reflector to an apertured cavity, adjusting the light path matching part to make the laser enter a resonant cavity composed of the apertured cavity and the reflector, and measuring the cavity loss L2 of the apertured diaphragm resonant cavity through the loss measurement system [4]; and calculating a difference between the cavity loss L2 and the cavity loss L1 to obtain the diffraction loss of the apertured diaphragm resonant cavity. The method has the advantages of strong operationality, small error and high measurement precision, solves a problem that the measuring diffraction loss of the laser gyro cannot be accurately measured in the prior art, and has good application values.

The present invention discloses a laser light source for implementing pulsed oscillation of laser light, which has a laser cavity in which a laser medium for generating emitted light with supply of excitation energy is placed on a resonance path; an excitation device for continuously supplying excitation energy to the laser medium; a monitor part for monitoring a power of light extracted at a middle point of the path of the cavity from the laser medium in accordance with the supply of the excitation energy by the excitation device; a Q-switch for modulating a cavity loss of the laser cavity; and a control part for performing such control as to stabilize a peak power or an energy of laser light pulses outputted in a state in which the cavity loss of the laser cavity is set at a second predetermined loss for oscillation of high-power pulses, based on the power of the emitted light monitored by the monitor part in a state in which the cavity loss of the laser cavity is set at a first predetermined loss for non-oscillation of high-power pulses.

An optically-pumped mode-locked fiber ring laser for optical clock recovery of multiple wavelength division multiplexed optical signals actively mode-locks a plurality of outputs of the laser as a plurality of recovered clocks for a plurality of the multiple wavelength division multiplexed optical signals. The laser cavity has a cavity length corresponding to an integer multiple of bit periods of at least one of the multiplexed optical signals for receiving a pre-amplified version of the plurality of wavelength division multiplexed optical signals to provide gain modulation through a phase-insensitive parametric amplification and recirculating a proportion of the output from the laser cavity back through the laser cavity for spatially mode-locking the output of the laser cavity as a recovered clock whereby the recovered optical clock each having a periodic train of optical pulses with a repetition rate corresponding to the clock rate of the corresponding multiplexed optical signal is generated by mode-locking of the optically-pumped laser produced by a spatial modulation of the phase-insensitive parametric gain produced by the pulsed nature of the wavelength division multiplexed optical signals. A nonlinear gain medium disposed in the cavity has a sufficiently large dispersion at all of the wavelengths corresponding to the multiple wavelength multiplexed optical signals for minimizing four-wave mixing crosstalk among the multiple wavelength multiplexed optical signals, among the recovered clocks, and between the plurality of multiple wavelength multiplexed optical signals and the recovered clocks. The gain medium is pumped by the plurality of pre-amplified multiplexed optical signals to provide efficient gain modulation through the phase-insensitive parametric amplification at a plurality of narrow wavelength bands, each of the plurality of narrow wavelength bands immediately adjacent to a wavelength of a corresponding optical signal and each of the plurality of narrow wavelength bands including a corresponding recovered optical clock wavelength, and each of the corresponding optical signals copropagating in the laser cavity through the nonlinear gain medium with the recovered optical clocks. A parametric optical amplifier or a Raman amplifier having an inhomogenously broadened gain amplifies the plurality of recovered clocks for compensating a portion of the cavity loss at all wavelengths of the plurality of recovered clocks. A wavelength selector passes the light at the plurality of wavelengths of the recovered clocks for recirculation in the laser cavity and preventing the light from the multiple wavelength division multiplexed optical signals and a plurality of idler waves generated by four wave mixing between the multiple wavelength division multiplexed optical signals and recovered optical clocks from recirculating in the laser cavity.

The invention discloses an automatic self-plugging rivet positioning mechanism which comprises a riveter. The riveter comprises a power pipe, the top of the power pipe is communicated with a positioning pipe, a rivet inlet pipe communicated with the positioning pipe is clamped on one side of the positioning pipe, a power device is fixedly mounted in the power pipe and penetrates the power pipe to be inserted into the positioning pipe, the top of the power device is fixedly connected with the bottom of a positioning device in the positioning pipe, the positioning device comprises a riveter pipe, and a moving positioning block is in slide connection with the bottom of the riveter pipe. By matching of the power pipe, the positioning pipe and the rivet inlet pipe, rivet feeding is realized, and problems of time consumption and labor consumption in manual operation are solved; by matching of the power device and the positioning device, rivet positioning is realized; by rivet positioning, the problem of short service life of the riveter due to cavity loss caused by rivets at inappropriate positions is reduced.

Dual-wavelength operation is easily achieved by biasing the gain section. Multiple gratings spaced apart from each other are separated from an output aperture by a gain section. A relatively low coupling coefficient, κ, in the front grating reduces the added cavity loss for the back grating mode. Therefore, the back grating mode reaches threshold easily. The space section lowers the current induced thermal interaction between the two uniform grating sections, significantly reducing the inadvertent wavelength drift. As a result, a tunable mode pair separations (Δλ) as small as 0.3 nm and as large as 6.9 nm can be achieved.

A spherical laser includes a transparent or semi-transparent outer spherical vessel having an internal cavity, an amplifying medium in the cavity, and means to excite the amplifying medium. The sphere is provided with a partially reflective coating to act as a spherical optical resonator. Excitation of the amplifying medium produces an optical gain. When the gain exceeds cavity losses and threshold conditions are met, lasing is supported. This creates a three-dimensional, spherically radiating emission, emulating a point source. The output is radially diverging, but is harnessed by enclosing the sphere within a mirrored ellipse to image the output to a point, or within a mirrored parabola to columinate the emission. A concentric, reflective inner sphere may be disposed in the cavity, with the amplifying medium lying between the two spheres. A voltage potential is applied between the spheres to excite the medium.