Abstract: A fiber optical device 1A includes an amplification optical fiber 10, a seed light source 15 for supplying pulse seed light to the optical fiber 10, excitation light sources 21 to 25 for supplying excitation light, a bleaching light source 40 for supplying bleaching light for reducing a light transmission loss caused by photodarkening, and a control device 50 that controls the operations of individual portions. The control device 50 divides a period between a first output light pulse and a succeeding second output light pulse into a first period which includes a time point immediately after the output of the first output light pulse and during which the population inversion is unsaturated, and a second period which includes a time point immediately before the output of the second output light pulse, and, to the optical fiber 10, supplies the bleaching light in the first period and supplies the excitation light in the second period.

Abstract: A fiber optical device 1A includes an amplification optical fiber 10, a seed light source 15 for supplying pulse seed light to the optical fiber 10, excitation light sources 21 to 25 for supplying excitation light, a bleaching light source 40 for supplying bleaching light for reducing a light transmission loss caused by photodarkening, and a control device 50 that controls the operations of individual portions. The control device 50 divides a period between a first output light pulse and a succeeding second output light pulse into a first period which includes a time point immediately after the output of the first output light pulse and during which the population inversion is unsaturated, and a second period which includes a time point immediately before the output of the second output light pulse, and, to the optical fiber 10, supplies the bleaching light in the first period and supplies the excitation light in the second period.

Abstract: In a longitudinal flexible composite optical medium (3) for use in a laser device, the longitudinal flexible composite optical medium includes a laser beam guide portion (1) containing a laser active material (11) and an excitation beam guide portion (2) for distributing and introducing an excitation beam into the laser beam guide portion. The laser beam guide portion and the excitation beam guide portion are uncoaxially arranged in parallel to each other and integrally coupled with each other. By winding or folding the composite optical medium, a laser structure of a predetermined shape is obtained.

Abstract: There are disclosed a converging device for converging a light having a high aspect ratio, and a light source module, a laser device and an optical signal amplifier using such converging device. A converging device has a converging portion for converging a light. The converging portion has an incident surface, a tip portion and a reflective surface for reflecting the light so that the light is transmitted toward the tip portion. The converging device has a guide portion provided in the reflective surface along a direction from the incident surface to the tip portion. The light transmitted in the converging portion is introduced to the guide portion and the light in the guide portion is reflected so as to be transmitted toward one end of the guide portion. The converged light is emitted from the tip portion or an end of the guide portion.

Abstract: A laser device that includes a laser beam guide portion (1) and an excitation beam guide portion (2) for confining an excitation beam and introducing the excitation beam into the laser beam guide portion (1) in a distribution state to perform laser oscillation or amplification. The excitation beam guide portion (2) is formed by winding or rounding a flexible beam guide member (21) having a ribbon-like or a sheet-like shape to form a thin integral body as a beam guide structure.

Abstract: There are disclosed a converging device for converging a light having a high aspect ratio, and a light source module, a laser device and an optical signal amplifier using such converging device. A converging device has a converging portion for converging a light. The converging portion has an incident surface, a tip portion and a reflective surface for reflecting the light so that the light is transmitted toward the tip portion. The converging device has a guide portion provided in the reflective surface along a direction from the incident surface to the tip portion. The light transmitted in the converging portion is introduced to the guide portion and the light in the guide portion is reflected so as to be transmitted toward one end of the guide portion. The converged light is emitted from the tip portion or an end of the guide portion.

Abstract: An array element examination method in which a relative position of an array element can be examined with a high resolution, in a broad range and relatively inexpensively. Lights from fibers of a fiber array are radiated to a lens array having optical axes corresponding to the fibers arranged substantially parallel with one another, and substantially parallel lights are fetched from the lens array. In order to prevent any trouble from occurring even if a photographing range is limited, images of the parallel lights from the lens array are formed on the substantially identical point by the image forming lens. The formed fiber images are photographed by a CCD camera, and relative positions of the elements are obtained from photographing signals by a computer. It is determined from the deviation from the identical point whether or not the fiber array is good.