A method for intracavity frequency conversion includes end-pumping a solid-state gain medium in a laser resonator with a pump laser beam to generate an intracavity laser beam circulating in the laser resonator, and frequency-converting a portion of the intracavity laser beam in a nonlinear crystal, located in the laser resonator, to generate a frequency-converted laser beam. The method controls the output power and at least one output beam parameter of the frequency-converted laser beam by adjusting (a) the pump power and (b) a resonator loss imposed on the intracavity laser beam. Taking advantage of both the pump laser beam and the intracavity laser beam contributing to thermal lensing in the gain medium, this control scheme is capable of controlling the output power and the output beam parameter(s) independently of each other.

Apparatuses and methods are disclosed for applying laser energy having desired pulse characteristics, including a sufficiently short duration and/or a sufficiently high energy for the photomechanical treatment of skin pigmentations and pigmented lesions, both naturally-occurring (e.g., birthmarks), as well as artificial (e.g., tattoos). The laser energy may be generated with an apparatus having a resonator with a sub-nanosecond round trip time.

Systems and methods for ring laser gyroscopes (RLGs) are provided. An RLG includes a traveling-wave resonator cavity with three or more mirrors and a gain medium positioned in the traveling-wave resonator cavity between two of the three or more mirrors. The gain medium is a solid-state gain medium or a nonlinear optical medium. The RLG further includes a first pump laser and a second pump laser to pump the gain medium in different directions and generate first and second lasing signals that traverse the traveling-wave resonator cavity in a opposite directions. The RLG further includes first and second photodetectors to measure levels of the first and second lasing signals. The RLG further includes at least one processor configured to adjust a power level of the first pump laser and/or a power level of the second pump laser based on the measured power levels of the first and second lasing signals.

A smart spool is configured to be optically coupled between a pumping light source and optical point-loss sources in an optical fiber transmission line. The smart spool comprises a probe signal transmitter that transmits an optical probe signal into the transmission line. An optical detector receives probe signals scattered in the transmission line. A loss-measuring device is coupled to the optical detector and operable to measure aggregate losses in the transmission line and report the aggregate losses to a network manager. The spool comprises a fiber of sufficient length to offset the aggregated losses to enable a distributed Raman amplifier to pump the transmission line. The smart spool prevents the distributed Raman amplifier from shutting down and allows the distributed Raman amplifier to achieve entitled gain by pumping the fiber in the spool.

A lasing device includes an active layer comprising a cholesteric liquid crystal material and a laser dye, and a liquid crystal cell including spaced apart substrates defining a cell gap in which the active layer is disposed. The substrates include electrodes arranged to bias the active layer into an oblique helicoidal (Ch.sub.OH) state. At least one substrate of the liquid crystal cell is optically transparent for a lasing wavelength range of the device.

A lasing device includes an active layer comprising a cholesteric liquid crystal material and a laser dye, and a liquid crystal cell including spaced apart substrates defining a cell gap in which the active layer is disposed. The substrates include electrodes arranged to bias the active layer into an oblique helicoidal (Ch.sub.OH) state. At least one substrate of the liquid crystal cell is optically transparent for a lasing wavelength range of the device.

A MOPA laser system that includes a seed laser configured to output pulsed laser light, an amplifier configured to receive and amplify the pulsed laser light emitted by the seed laser; and a pump laser configured to deliver a pump laser beam to both the seed laser and the amplifier and a variable attenuator configured to eliminate missing Q-switched pulses.

Apparatuses and methods are disclosed for applying laser energy having desired pulse characteristics, including a sufficiently short duration and/or a sufficiently high energy for the photomechanical treatment of skin pigmentations and pigmented lesions, both naturally-occurring (e.g., birthmarks), as well as artificial (e.g., tattoos). The laser energy may be generated with an apparatus having a resonator with a sub-nanosecond round trip time.

A laser irradiating device preferably includes: a reflector having a receiving space formed therein; a flash lamp inserted and mounted in the reflector to generate light; a laser rod for resonating light incident from the flash lamp to emit a laser; a capacitor for storing, for a predetermined time interval, voltage to be supplied to the flash lamp; a digital variable resistor unit for outputting different voltages according to configured resistance values; a voltage increasing unit for increasing voltage input from the digital variable resistor unit and supplying the increased voltage to the capacitor; a control unit which stores resistance values corresponding to laser irradiating levels and configures a resistance value corresponding to the configured laser irradiating level; and a trigger circuit unit turned on according to a control of the user to supply a charge voltage of the capacitor to the flash lamp.

A master oscillator configured as a seed laser for a laser optical module includes a reduced size, temperature controlled non-planar ring oscillator, a piezo-electric transducer mounted on the non-planar ring oscillator, a pump laser diode, and coupling optics configured to couple a laser output of the pump laser diode to an end face of the non-planar ring oscillator. The pump laser diode may operate as a single-mode pump.