A new type of unstable resonator has been developed that permits multiple-selected-line operation. Selected-line operation is obtained with a diffraction grating that is oriented at an angle that is different from the Littrow angle. Secondary feedback mirrors at the appropriate angles provide an independent threeelement cavity for each wavelength selected. The off-Littrow configuration is less efficient than a singleline cavity at the Littrow angle because there are secondary zero-order beams at each wavelength as well as a primary zero-order beam at all selected wavelengths. In the limit of a high gain this loss in efficiency is shown to be significantly reduced. Two types of multiple-selected-line unstable resonators are considered: an edge-coupled design, which produces an annular beam with a 45 degrees output coupling mirror, and a continuously coupled design, which uses the primary zero-order beam as output. Experiments have been carried out with a multiple-selected-line unstable resonator on a cw HF laser. Selected-line operation was obtained on the P(2) (5) and P(1) (6) HF transitions in a continuously coupled design.

A multiple-selected-line unstable resonator

The invention provides an annular-spot chip amplifier. By the annular-spot chip amplifier, annular laser beams, with high beam quality and low power, obtained by the aid of an unstable cavity can pass through different aperture areas of a same chip gain medium or chip gain medium sequence conveniently and repeatedly in different beam sizes, equal-flux laser extraction with high laser power density is realized, ASE (amplified spontaneous emission) is suppressed effectively, high optical to optical conversion efficiency is realized, and temperature gradient and temperature to optical distortion caused by non-uniform radial laser on a chip can be further avoided.

Annular-spot chip amplifier

The invention discloses a test system for testing the grating diffraction efficiency. The system comprises a wavelength tunable laser device, a polarization control element, a light splitting device and a rotatable diffractive element. The wavelength tunable laser device, the polarization control element, the light splitting device and the rotatable diffractive element are arranged on an optical axis of an optical path in sequence. The system further comprises two light energy detectors. One of the two light energy detectors is matched with the light splitting device to enable a reference light beam to be separated from the light splitting device to directly enter the first light energy detector, while the other one of the two light energy detectors is matched with the diffractive elementto enable a test light beam split from the light splitting device to shoot into the diffractive element and then enter the second light energy detector after being diffracted by the diffractive element. The test system is high in laser wavelength precision, wide in line width and adjustable in polarization direction. By means of the test system, the spectrum, the angle and the polarization characteristics of the grating high-precision diffraction efficiency can be obtained. The test system is simple in configuration, convenient in operation and strong in environment adaptability. The application requirements in the field of high-power laser and spectral analysis can be met. The test system can be applied to the fields of spectral synthesis and spectral analysis.

Test system and test method for testing grating diffraction efficiency

The embodiment of the invention discloses a space-based laser defensive system The space-based laser defensive system comprises a high-altitude airship (HAA) The HAA comprises a balloon filled withascending gas and a focusing optical device for focusing laser beams from the exterior of the HAA to a target position The laser beams can reach the HAA from a space-based laser (SBL) kept in a geosynchronous orbit By adopting the technical scheme, the HAA can keep close to a known launching site or submarine launching target missiles In this way, the HAA can certainly intercept and destroy thetarget missiles

Laser defense system and high altitude airship

The invention provides an adjusting device and an adjusting method for a ring-down cavity so as to solve the technical problems that an existing adjusting process of the ring-down cavity is lack of convenient and reasonable adjusting equipment and a high-precision and high-stability adjusting process cannot be formed. The device comprises an indicating light source generator, a small aperture slot, a visible light frequency band reflector group, a detection light source reflector, a detector and an adjustable small aperture slot, wherein the indicating light source generator is used for forming an indicating light source of a visible light frequency band; the small aperture slot is used for restricting indicating light and judging adjusting accuracy on an indicating light source light path; the visible light frequency band reflector group is used for adjusting the direction of the indicating light source light path; the detection light source reflector is used for changing a detectionlight source light path on the indicating light source light path to form a reflection light path of the detection light source light path; the detector is used for receiving detection light on the reflection light path to carry out signal identification; and the adjustable small aperture slot is used for optical axis calibration of detection light output by the ring-down cavity and adjacent indicating light. An accessory component is avoided from being added between a detection light source and the ring-down cavity, the system-level reliability of the ring-down cavity is guaranteed, and the personal error and adjusting difficulty in the adjusting process of the ring-down cavity are overcome.

Adjusting method and adjusting device for ring-down cavity

The invention provides a long-time iodine flow supply device, and relates to the technology of gas supply of a continuous wave oxygen-iodine chemical laser. The main body of the device has two parts: an electric heating iodine vapor storage tank and a combustion chamber for the combustion of two types of gas. The electric heating iodine vapor storage tank enables solid iodine to be heated to a certain temperature and enables the solid iodine to be changed into liquid iodine. Moreover, there is iodine vapor with a certain saturated vapor pressure on the liquid level. The combustion chamber is a closed space which is used for the combustion of carbon monoxide and oxygen, and the generated high-temperature and high-pressure gas enters the iodine vapor storage tank after the temperature adjustment through diluent gas. High-temperature carbon dioxide gas enters the liquid phase of the iodine vapor storage tank and then forms bubbles, thereby enabling heat energy to be transferred to the liquid iodine and enabling the iodine to be vapored into iodine vapor, wherein the bubbles comprise iodine vapor with a certain density. When the bubbles continue to rise in the liquid phase, the phenomenon of mass and heat transfer continues to happen till the balance is reached. The bubbles flow out from the liquid phase, enter a gas phase, pass through a gas supply pipe and then enter a laser main body.

Long-time iodine flow supply device

The present invention relates to an RTP electrooptical modulating Q airflow hydrogen fluoride laser; the laser uses a stable cavity structure; and a planoconcave reflective mirror, a gain medium area, a Brewster piece, a planoconvex lens, a planoconcave lens, an electrooptical Q switch, a 1/4 wave plate, and a plane diffraction grating are successively disposed along a forward direction outputting a laser light The laser of the present invention uses the electrooptical effect of the RTP crystal to modulate Q, and changes a phase delay of the RTP crystal through applying a modulating signal on a drive power source, to control oscillating characteristics of hydrogen fluoride oscillating light of the crystal to achieve periodical mutation of high and low Q values of the resonant cavity, thereby achieving the output of a pulse for modulating Q of the hydrogen fluoride laser light The laser has the following advantages: short switch time, high peak power, and high synchronism and stability of the laser light, etc, and can be applied to fields such as optoelectrionic countermeasure, laser light detecting, and component analysis

RTP electrooptical modulating Q airflow hydrogen fluoride laser

The invention relates to a resonant cavity for pulse and line selection output of an airflow hydrogen fluoride laser. The resonant cavity adopts a folded cavity structure. A rotatable first plane reflector, a second acoustic-optic modulator, a first acousto-optic modulator, a concave lens, a convex lens, a polarizer, a second plane reflector, a third plane reflector, a fluoride hydrogen gain medium region, and a plane-concave output mirror are coaxially arranged in sequence along the heading direction of output laser. According to the laser resonant cavity of the invention, line selection output of a laser is realized based on the fact that an acousto-optic medium in the second acoustic-optic modulator diffracts laser of different wavelengths at different angles and through scanning of the rotatable reflector, and pulse output of the laser is realized by using the first acousto-optic modulator to Q-modulate the laser. The resonant cavity has the advantages of low power consumption, good pulse stability and reliability, and the like. High-repetition-frequency and high-peak-power line selection output of an airflow hydrogen fluoride laser can be realized. The resonant cavity can be applied to laser countermeasure, laser detection and other fields.

Resonant cavity for pulse and line selection output of airflow hydrogen fluoride laser

An experimental study of combustion-driven HBr chemical laser based on D2/NF3 combustion was carried out. The exotherm of the reaction system was analyzed, and the thermal blockage issue of supersonic flow was solved by adjusting the buffer coefficient ω. By optimizing the laser operating conditions, a maximum HBr laser output of 141W was obtained, with the primary laser lines being HBr P1(5) , P1(6) , and P3(6).

Experimental study on combustion-driven hydrogen bromide (HBr) chemical laser

The present invention discloses a hydrogen bromide chemical laser based on singlet oxygen transfer energy. The vibrational excitation hydrogen bromide molecule generated by near resonance energy transfer from an excited singlet oxygen molecule O2 (a) to a ground state hydrogen bromide molecule is taken as the light out media of the laser. The singlet oxygen molecule is generated by a chemical reaction, and the singlet oxygen generator of the chemical reaction is the very mature technology in an oxygen iodine chemical laser. The device is formed by a singlet oxygen generator, a supersonic mixing nozzle, an optical resonator, a measurement and control system, an air source supply system and a vacuum system. According to the hydrogen bromide chemical laser, through using the singlet oxygen molecule as an energy storage particle, the intermediate infrared laser output with rich spectrum can be realized by a pumped ground state hydrogen bromide molecule.

Hydrogen bromide chemical laser based on singlet oxygen transfer energy

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