Image relaying is presented as a technique for aligning beams onto mm-sized target of high power laser. On the basis of summarizing the preceeding work on the near-field image relaying of multiple spatial filters, the far-filed image relaying is suggested firstly. The near-field and far-field image relaying properties of multiple spatial filters in laser beams automatic alignment system are analyzed. A geometrical optics approach and an ABCD ray matrix theory are used throughout. The reasonable and optimum scheme for automatically aligning multi-pass beam paths is presented and demonstrated on the multi-pass amplifier system of the SG-III prototype.

Image relaying is presented as a technique for aligning beams onto mm-sized target of high power laser. On the basis of summarizing the preceeding work on the near-field image relaying of multiple spatial filters, the far-filed image relaying is suggested firstly. The near-field and far-field image relaying properties of multiple spatial filters in laser beams automatic alignment system are analyzed. A geometrical optics approach and an ABCD ray matrix theory are used throughout. The reasonable and optimum scheme for automatically aligning multi-pass beam paths is presented and demonstrated on the multi-pass amplifier system of the SG-III prototype.

The laser beams automatic alignment system is used to adjust beam lines automatically in the high power laser fa2cility for inertial confinement fusion. Image processing is one of the key techniques in laser beam automatic alignment. Consider2ing the SG-Ⅲ, combining different kinds of methods in image processing such as threshold, gravity model, median filter, cir2cle fitting and so on, a reasonable scheme for automatic alignment was presented. It was demonstrated on the simulation experi2ment system. Results indicated that beam paths adjustment can be finished in 15 minutes by the automatic alignment system.The precision of the near field adjustment was less than 0.5 % of the spot. The accuracy of the far field adjustment was lessthan 0.3″. Requirements of the SG-Ⅲprototype facility are met.

Large, high-power laser amplifiers use the imaging properties of multiple spatial filters. Spatial filtering has been shown to control instabilities; spatial filters preserve the transverse intensity profile of a high power beam as it propagates long distances through nonlinear elements as well. In this paper, image relaying is presented as a technique for aligning beams onto mm-sized target. On base of summarizing the preceding work on the near-field image relaying of multiple spatial filters, the far-field image relaying is suggested firstly. The application of near-field and far-field image relaying properties of multiple spatial filters in laser beams automatic alignment system is analyzed. A geometrical optics approach and an ABCD ray matrix theory are used throughout. A reasonable and optimized scheme for automatic aligning multipass beam paths is presented. It is demonstrated on the multipass amplifier experimental system of the SG-III prototype.

Beam automatic alignment system is applied in high power laser facility for inertial confinement fusion. The basic principles and key techniques are researched. The evolution of beam automatic alignment systems abroad is introduced and the future development of the automatic alignment system in high power laser facility is prospected.

A laser alignment system is applied to a high power laser facility for inertial confinement fusion. A design of the automated, close-loop laser beam alignment system is described. Its function is to sense beam alignment errors in a laser beam transport system and automatically steer mirrors preceding the sensor location as required to maintain beam alignment. The laser beam is sampled by a sensor package, which uses video cameras to sense pointing and centering errors. The camera outputs are fed to a personal computer, which includes video digitizers and uses image storage and software to sense the centroid of the image. Signals are sent through the computer to a stepper motor controller, which drives stepper motors on mirror mounts preceding the beam sampling location to return the beam alignment to the prescribed condition. Its optical principles and key techniques are given. The pointing and centering sensitivities of the beam alignment sensor package are analyzed. The system has been verified on the multi-pass amplifier experimental system.

Laser beam automatic alignment systems are used to align the SG-Ⅲ prototype facility laser. Considering the facility qequirement, combining the key technique of automatic alignment, according to the image relay of the pinhole, utilizing the optical position and the spatial location of the four pinholes of the main spatial filter in the four-pass beam in the SG-Ⅲ, this paper presents a reasonable scheme for automatic aligning in the four-pass amplifier, which has been fully checked on the multi-pass amplifier experiment system.The centering sensitivities of the system are less than 0.5% of the beam diameter. The pointing sensitivities of the system are less than 10μm.

Alignment accuracy of the cavity mirror in multipass amplifier is very high. Aiming at the requirements on alignment precision of cavity mirror in high power lasers, using image relaying of pinholes and the principle of beam automatic alignment, a scheme to align the cavity mirror is designed. It has been demonstrated on the simulation experiment system of the SG-Ⅲ prototype facility. The main amplifier's adjustment can be finished in 15min. The centering precision of the system is less than 0.5% of the beam diameter. The pointing precision of the system are less than 0.3".

A laser beam automatic alignment system is applied in a multipass amplifier of the SG-III prototype laser. Considering the requirements of the SG-III prototype facility, by combining the general techniques of the laser beam automatic alignment system, according to the image relayed of the pinholes in the spatial filter, and utilizing the optical position and the spatial distribution of the four pinholes of the main spatial filter in the multipass amplifier of the SG-III prototype, a reasonable and optimized scheme for automatic aligning multipass beam paths is presented. It is demonstrated on the multipass amplifier experimental system. ?2004 Society of Photo-Optical Instrumentation Engineers.

光束自动准直系统应用于惯性约束聚变的高功率激光装置,研究了光束自动准直的原理和关键技术,介绍了国外光束自动准直系统的发展状况,展望了高功率激光装置自动准直系统的未来发展趋势。