Abstract: An optical system on which polarized light is incident includes a first reflecting member that is rotationally symmetric with respect to a first axis and has a first reflecting surface that reflects the polarized light to emit reflected light as first reflected light, and a second reflecting member that is rotationally symmetric with respect to the first axis and has a second reflecting surface that reflects the first reflected light to emit reflected light as second reflected light. A cross-sectional shape of the first reflecting surface cut along a plane parallel to the first axis is concave. A cross-sectional shape of the second reflecting surface cut along the plane parallel to the first axis is convex. An optical path of the first reflected light is parallel to the first axis. An optical path of the second reflected light is directed outward from the first axis.

Abstract: A blazed diffractive optical element includes: a blazed diffraction grating pair that includes a first blazed member and a second blazed member and functions as a diffraction grating with the first blazed member and the second blazed member; and an interlayer that is positioned between the first blazed member and the second blazed member, in which in a case where a refractive index of the first blazed member is represented by Na, a refractive index of the interlayer is represented by N, and a refractive index of the second blazed member is represented by Nb, a magnitude relationship of Na>N>Nb is satisfied.

Abstract: Disclosed are a solid-state laser device having an advantage of achieving simplification of a configuration and reduction in size, and a photoacoustic measurement device. In a solid-state laser device which accommodates a solid-state laser medium and an excitation light source having a rod-shaped portion, the excitation light source is provided to be pulled out of a laser chamber. An optical element which bends light is provided at a position separated from the rod-shaped portion such that at least a part of the optical element and at least a part of the rod-shaped portion are at the same position in the longitudinal direction of the rod-shaped portion. One resonator mirror is disposed at a position where bent light is incident. Optical components between the optical element and the resonator mirror are provided at positions separated from a path along which the excitation light source is pulled out.

Abstract: Disclosed are a solid-state laser device having an advantage of achieving simplification of a configuration and reduction in size, and a photoacoustic measurement device. In a solid-state laser device which accommodates a solid-state laser medium and an excitation light source having a rod-shaped portion, the excitation light source is provided to be pulled out of a laser chamber. An optical element which bends light is provided at a position separated from the rod-shaped portion such that at least a part of the optical element and at least a part of the rod-shaped portion are at the same position in the longitudinal direction of the rod-shaped portion. One resonator mirror is disposed at a position where bent light is incident. Optical components between the optical element and the resonator mirror are provided at positions separated from a path along which the excitation light source is pulled out.

Abstract: An optical tomographic image production apparatus includes an optical probe, in which a light-transmitting area that transmits measurement light and a light-blocking area that blocks the measurement light are formed. The light-blocking area is provided at a start position and an end position of the light-transmitting area. A tomographic image processing means detects an interference signal or tomographic information when the light-blocking area is irradiated with the measurement light. Further, the tomographic image processing means detects, based on the detected interference signal or tomographic information, interference signals or tomographic information obtained when the light-transmitting area is irradiated with the measurement light to produce a tomographic image in the light-transmitting area.

Abstract: An optical probe includes: an optical fiber; a substantially cylindrical ferrule integrally fixed to the optical fiber in the vicinity 2of the distal end of the fiber; a distal optical system for deflecting laser emitted from the optical fiber toward a subject to be measured; a holding portion for holding the distal optical system, the holding portion being supported by the ferrule rotatably about the optical axis of the optical fiber; a rotating oscillator slidably engaging with the outer circumferential surface of the ferrule; a driving unit for imparting oscillation in the direction of the optical axis to the rotating oscillator; and a coupling member for coupling the holding portion with the rotating oscillator elastically in the direction of the optical axis. The rotating oscillator rotates about the optical axis and reciprocates in the direction of the optical axis due to the oscillation applied from the driving unit.

Abstract: An optical tomographic image production apparatus includes an optical probe, in which a light-transmitting area that transmits measurement light and a light-blocking area that blocks the measurement light are formed. The light-blocking area is provided at a start position and an end position of the light-transmitting area. A tomographic image processing means detects an interference signal or tomographic information when the light-blocking area is irradiated with the measurement light. Further, the tomographic image processing means detects, based on the detected interference signal or tomographic information, interference signals or tomographic information obtained when the light-transmitting area is irradiated with the measurement light to produce a tomographic image in the light-transmitting area.

Abstract: An OCT optical probe to be inserted into a subject includes: a cylindrical sheath to be inserted into a subject; an optical fiber disposed in the internal space of the sheath; a rotatably-supporting portion fixed to the optical fiber in the vicinity of a distal end of the optical fiber; a distal optical system to deflect light emitted from the distal end of the optical fiber toward the subject; a holding portion to hold the distal optical system such that the optical system is rotatably supported by the rotatably-supporting portion; and a flexible shaft covering the optical fiber in the internal space, wherein the holding portion is fixed to a distal end of the flexible shaft. Using the OCT optical probe of the invention, the problem of degradation of measurement accuracy due to optical insertion loss and optical reflection loss at a rotary joint can be eliminated inexpensively and safely.

Abstract: The illuminating system comprises a linear light source, and a light guide member with the light source placed beside a side face thereof, in which the top face and the bottom face of the light guide member are generally parallel to each other and in which slits made of a different material or air are arranged at specified intervals in the top face of the light guide member. Therefore, most of light propagating within the light guide member is totally reflected at the slits formed in the light guide member so as to be outputted from the light guide member, thereby illuminating a reflecting plate. Its reflected light is incident again on the light guide member and the resulting totally reflected light is transmitted to the observer's side at places other than the slits, while the observer's field of view is not obstructed at the slit portions.

Abstract: A reflective liquid crystal lighting device includes a light source, a tabular transparent light guide for receiving light emitted from the light source at a side surface and for emitting illuminating light from the back surface thereof, and a transparent material filled between the light guide and the reflective liquid crystal provided at the back side thereof. The reflective liquid crystal is viewed from the side of the front surface of the light guide through the transparent material.

Abstract: The illuminating system comprises a linear light source, and a light guide member with the light source placed beside a side face thereof, in which the top face and the bottom face of the light guide member are generally parallel to each other and in which slits made of a different material or air are arranged at specified intervals in the top face of the light guide member. Therefore, most of light propagating within the light guide member is totally reflected at the slits formed in the light guide member so as to be outputted from the light guide member, thereby illuminating a reflecting plate. Its reflected light is incident again on the light guide member and the resulting totally reflected light is transmitted to the observer's side at places other than the slits, while the observer's field of view is not obstructed at the slit portions.

Abstract: A highly efficient, luminous and energy-saving panel-form illuminating system suitable for mass-production, comprising at least a photoconductor, a linear light source at one side of the photoconductor, and a reflector; wherein grooves or protrusions are formed on the bottom surface of the photoconductor.

Abstract: A low-cost wide-angle lens assembly being comprised of a decreased number of lenses yet capable of properly correcting optical aberrations. The second lens in each lens group from the minimum to the maximum horizontal viewing angle is commonly used, and the first lens in each lens group from a reference angle to the maximum horizontal viewing angle is commonly used, thus reducing the total number of required lenses. Aberrations are favorably corrected by satisfying predetermined conditions as to focal distances and back focuses of the lenses.

Abstract: An efficient, luminous and energy-saving panel-form illuminating system suitable for mass-production, comprising at least a photoconductor, a linear light source at one side of the photoconductor, and a reflector; wherein grooves or protrusions are formed on the bottom surface of the photoconductor.