Abstract: A passive eight-pass solid-state laser amplifier is constructed using a quarter-wave plate (11), a total reflection mirror (12), a polarization beam splitter (5), and a total reflection mirror (6) while input/output faces of a hexagonal zigzag slab solid-state laser medium (15) optically pumped are kept nearly perpendicular to pulsed laser light. Thermal birefringence takes place in the laser medium (15) optically pumped with good symmetry by flash lamps or LDs (9) and is compensated for by a quartz 90.degree. rotator (10). Linearly s-polarized laser light reflected by a polarization beam splitter (3) is output as pulsed laser output light (13) to the outside. Owing to this, saturation laser amplification can be achieved using output laser light from a pulsed laser oscillator of relatively low output, as source light.

Abstract: A sample is placed between a circular polarizer and an analyzer in an optical path between a monochromatic light source and a two-dimensional optical receiver. Parallel beams emitted from the monochromatic light source are converted into circularly polarized light by the circular polarizer. After transmitting the sample, the light is guided to the analyzer. While rotating the analyzer about the axis of the beams, image data are detected by optical receiver at a step of a regular rotation angle, and the detected image data are sampled to be sent to an image processing device in the next stage. On the basis of the image data, an operation is conducted on each pixel to obtain a relative phase difference due to birefringence of the sample, the two-dimensional birefringence distribution including the sign of the relative phase difference, and also the principal axis direction.

Abstract: The invention is directed to a focusing optical system for semiconductor lasers, which is regulated in terms of magnification power in both its directions normal to the optical axis, so that the back focus of sufficient magnitude can be made equal in both the directions and the magnitude of aberration can be regulated to achieve an improvement in focusing efficiency, and in which a light beam from a semiconductor laser having varying exit angles in the horizontal and vertical directions is focused on a spot having substantially equal diameters in the horizontal and vertical directions. This focusing optical system comprises first lens unit L1 including a rotation asymmetric lens having positive power in the direction defined by a large exit angle at which a laser beam emanates from the laser, a second lens unit L2 including at least one lens of negative power, and a third lens unit L3 that is a rotation asymmetric lens unit having positive power in the directions defined by both large and small exit angles.