摘要:
Method for producing ultraintense laser pulses in which Stimulated Raman Back-Scattering (SRBS) amplifies and compresses a seed pulse, as well as an inventive compact plasma device which may implement the method. SRBS may be achieved by counter-propagating the seed pulse and a pump pulse through a few millimeter-long plasma having a plasma frequency equal to the difference between the pump and the seed pulse frequencies. Dichroic mirrors may be arranged to provide two amplifying and compression passes through the plasma, allowing greater seed pulse amplification by mitigating Landau damping within the plasma that would occur in a single pass of a plasma of double the length. Alternate examples provide for 2n number of amplification and compression passes by providing n short plasma columns, where n≥2, and additional, appropriately arranged dichroic mirrors. The compact size of the device, and the ultraintense, ultrashort pulses it emits, suit the device to dermatological applications.
摘要:
A method of generating Raman laser for inducing fluorescence of pyrene and a system thereof is disclosed. The system comprises a pulsed laser, a frequency doubling crystal, a frequency quadrupling crystal, a light filter unit, a Raman cell, a prism, an optical diaphragm, an object lens and an optical fiber. The method of the present invention comprises the steps of emitting a laser beam pulse through the crystals as mentioned above such that a mixture of lasers of different wavelength is generated. The light filter unit is used to obtain a pure pump laser from the mixture of lasers. Finally, the Raman laser is obtained by directing the pump laser into a Raman cell, extracting different orders of stimulated Raman scattering lasers emitted from the Raman cell by the prism and selecting a predetermined order of stimulated Raman scattering laser by the optical diaphragm.
摘要:
A method of generating Raman laser for inducing fluorescence of fluoranthene and a system thereof is disclosed. The system comprising a pulsed laser, a frequency doubling crystal, a frequency quadrupling crystal, a light filter unit, a quarter-wave plate, a Raman cell filled with deuterium gas( ), a light dispersion device and an optical diaphragm. The method of the present invention comprises the steps of emitting a laser beam pulse through the crystals as mentioned above such that a mixture of lasers is generated. The light filter unit and the quarter-wave plate are used to obtain a circular or ellipsometric polarized pump laser from the mixture of lasers. Finally, the Raman laser is obtained by directing the pump laser into a Raman cell filled with deuterium gas, extracting different orders of stimulated Raman scattering lasers emitted from the Raman cell by the light dispersion device and selecting the desired order of stimulated Raman scattering laser by the optical diaphragm.
摘要:
A laser amplifier system is presented including a pump regenerative amplifier. The amplifier generally has a cavity defined by a pair of end cavity mirrors between which an amplified pump pulse oscillates. The amplifier also includes an interaction cell with a tunable gain medium amplifies laser pulses (e.g., Raman gain). The interaction cell may be positioned within the pump amplifier cavity and an input pulse may be injected into the cavity of the amplifier to transit through the tunable gain medium of the interaction cell. A pump pulse transfers energy via interaction with the input pulse (e.g., Raman interaction) as the pulses counter-propagate through the gain medium of the interaction cell. Amplification of output laser pulses, however, is generally achieved according to the wavelength of the pump laser pulses thereby providing a wavelength dependent, or “tunable”, means for amplifying laser pulses.
摘要:
An optical wave generator comprising a first-level Raman sideband generator (RSBG). The first-level RSBG comprises a first hollow-core photonic crystal fibre HCPCF (203) arranged to be filled with a Raman active gas and a first two-pump continuous wave (CW) laser source (200) having a first pump laser beam (201) at a first frequency and a second pump laser beam (202) at a second frequency, the laser source being arranged to excite the first HCPCF to generate a Raman sideband spectrum comprising a first plurality of spectral components.
摘要:
The invention is in the field of laser radiation generation in bands II and III, and relates to a device for generating laser radiation in the infrared having means for modifying the amplified-radiation frequency and using the Raman effect, characterized by additionally having at least one diode able to emit laser radiation in the 1.8-2.1 μm frequency range, at least one current generator able to generate current levels at an adjustable repetition rate, means for supplying said current levels to said diode, and means for amplifying the laser radiation emitted by said diode and comprised of at least one fiber doped with an ion having laser activity in the diode emission range.
摘要:
A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.
摘要:
A low-temperature Raman laser apparatus that avoids an increase in the pump light power, which would otherwise be needed under room temperature conditions, and eliminates the problems of instability of the equipment and complicatedness of the operation under liquid nitrogen cooling conditions and also lowers the cost, which has heretofore been high due to the consumption of liquid nitrogen, and that is capable of stably and efficiently effecting Raman conversion. The low-temperature Raman laser apparatus has a Raman cell (1) filled with a Raman conversion medium to convert the wavelength of incident pump light by the Raman conversion action of the Raman conversion medium. A heat absorbing member (2) or (3), through which a brine cooled by a brine refrigerator (4) circulates, is provided around the Raman cell (1) to cool the Raman conversion medium to a temperature in the range of from 200.degree. K. to 300.degree. K.
摘要:
A laser includes a gas enclosure placed in an optical cavity and receiving a pump beam to generate at least one first-order and one second-order Stokes wave. One of the mirrors of the cavity is transparent to wavelengths which are higher than the first-order Stokes wave.
摘要:
A single focus backward Raman laser that is a compact, efficient apparatus for converting light at a first wavelength provided by a pump laser to light at a Raman-shifted wavelength. The laser is comprised of a gas cell, two lenses, a feedback mirror, an optical isolator, and a dichroic mirror, and the gas cell contains a Raman gas medium. The Raman gas medium may be methane, hydrogen, or deuterium, for example. The two lenses bring the pump and Raman light to a single focus in the gas cell and also recollimate the light after it exits the cell. The optical isolator is used to prevent the backward-scattered pump light from reentering the pump laser. The dichroic mirror is used to reflect out the backward-scattered Raman light, while transmitting the pump laser light. The present laser has a much improved beam divergence and is much less sensitive to optical misalignments than conventional Raman half-resonator designs. The present laser is also less complex and is more compact than a multiple focus backward Raman laser, with substantially identical Raman conversion efficiency and beam divergence. The present laser is adapted to replace the Raman half-resonator and the multiple focus backward Raman laser in high pulse repetition rate (>1 Hz), medium-energy (.ltoreq.100 mJ, 1.54 .mu.m) eyesafe laser designs.