Abstract: Provided is an optical connector including: an SI-type light source side optical fiber which is disposed on the light source side and an SI-type light receiving side optical fiber which is disposed on the light receiving side. Both optical fibers are optically coupled to each other by disposing an end surface of the light source side optical fiber and an end surface of the light receiving side optical fiber so as to face each other. The light source side optical fiber and the receiving side optical fiber are attachable to and detachable from each other. The light source side optical fiber includes a taper portion in which the diameter of the core portion increases toward the end surface of the light source side optical fiber.

Abstract: There is provided a mode locked laser device including: a cavity, the cavity having a semiconductor saturable absorbing mirror and a negative dispersion mirror that controls group velocity dispersion within the cavity, disposed in a straight line; a solid-state laser medium, disposed in the cavity and outputting oscillating light due to excitation light being incident thereon; an excitation unit that causes the excitation light to be incident on the solid-state laser medium; and a cavity holder, the light incident face of the semiconductor saturable absorbing mirror attached to one end of the cavity holder, the negative dispersion mirror attached to the other end of the cavity holder, and the cavity holder integrally supporting the semiconductor saturable absorbing mirror and the negative dispersion mirror.

Abstract: In a mirror including a substrate and a dielectric multilayer coating structure formed on the substrate, the multilayer coating structure includes two mirror-function layer portions, each formed by a plurality of layers deposited one on another, and a cavity layer that is arranged between the two mirror-function layer portions, and which causes light having a predetermined wavelength to resonate between the two mirror-function layer portions. Further, a dispersion value with respect to the light having the predetermined wavelength is in the range of ?600 fs2 to ?3000 fs2 and a reflectance with respect to the light having the predetermined wavelength is in the range of 97% to 99.5%.

Abstract: A light diffusing element diffuses light output from an output facet of an optical fiber that enters the light diffusing element at a first end and outputting the diffused light from a second end. The light diffusing element is equipped with a semireflective surface for reflecting a portion of the light, provided at a predetermined portion of the light diffusing element corresponding to the core of the output facet. The semireflective surface intersects at least with the optical axis of the optical fiber. Thereby, propagation of light in directions away from the optical axis of the optical fiber can be promoted during the step of reflecting the portion of the light that enters the light diffusing element.

Abstract: An endoscopic light guide for guiding illumination light to an observation target is equipped with: an optical fiber; and a radiation mode inducing means for causing propagation mode light propagating through the optical fiber to make side face radiation in the vicinity of an output facet of the optical fiber through which the propagation mode light exits, thereby converting the propagation mode light to radiation mode light such that the radiation mode light can be utilized as the illumination light.

Abstract: An electroluminescence device (1) realizes high light emission efficiency, high durability, and high extraction efficiency. The device includes electrodes (11, 17); a plurality of layers (12 through 16) that are deposited between the electrodes (11, 17); and a light emitting region (14) between the plurality of layers (12 through 16). The light emitting region (14) emits light by application of an electric field between the electrodes (11, 17). The thickness and the refractive index of each of the plurality of layers (12 through 16) satisfy a resonance condition in the electroluminescence device (1) that makes a region in which the intensity of the electric field of a standing wave (19) by the light emitted from the light emitting region (14) is the highest substantially coincide with the light emitting region (14). A metal member (20) that induces plasmon resonance on the surface thereof by the emitted light is arranged in the vicinity of the light emitting region (14).

Abstract: In a mode-locked laser-diode-excited laser apparatus: a solid-state laser medium is arranged at a distance of at most twice the Rayleigh range from a saturable absorbing mirror with a depth of absorbing modulation of at least 0.4%; the total intracavity dispersion is smaller than zero and makes oscillating light have such a pulse bandwidth that the saturable absorbing mirror can suppress a background pulses other than soliton pulses repeated with a fundamental repetition period, and the magnitude of the total intracavity dispersion has a predetermined relationship with a pulse width of the oscillating light; and an output mirror is a negative-dispersion mirror being constituted by two multilayer mirrors and a cavity layer sandwiched between the two multilayer mirrors, and causing a mirror dispersion of ?3000 fsec2 to ?600 fsec2 and realizes a reflectance of 97% to 99.5%.

Abstract: In a mode-locked laser-diode-excited laser apparatus: a solid-state laser medium is arranged at a distance of at most twice the Rayleigh range from a saturable absorbing mirror with a depth of absorbing modulation of at least 0.4%; the total intracavity dispersion is smaller than zero and makes oscillating light have such a pulse bandwidth that the saturable absorbing mirror can suppress a background pulses other than soliton pulses repeated with a fundamental repetition period, and the magnitude of the total intracavity dispersion has a predetermined relationship with a pulse width of the oscillating light; and an output mirror is a negative-dispersion mirror being constituted by three or more multilayer mirrors and cavity layers arranged at predetermined intervals between the three or more multilayer mirrors, and causing a mirror dispersion of ?3000 fsec2 to ?600 fsec2 and realizes a reflectance of 97% to 99.5%.

Abstract: A mode-locked solid-state laser apparatus having a resonator which includes a solid-state laser medium, a saturable absorption mirror, and a negative group dispersion element therein, in which the solid-state laser medium and the saturable absorption mirror are disposed at a distance not greater than twice a Rayleigh length which is determined by the beam radius of oscillation light formed at the saturable absorption mirror. The apparatus further includes a dichroic mirror in the resonator that reflects excitation light inputted from a direction crossing the optical axis of the resonator toward the solid-state laser medium and transmits oscillation light.

Abstract: In a soliton mode-locked solid-state laser apparatus having a resonator which includes therein a solid-state laser medium, a saturable absorption mirror, and a negative group velocity dispersion element, the solid-state laser medium and saturable absorption mirror are disposed in close proximity to each other at a distance not greater than twice a Rayleigh length. Then, the absorption modulation depth ?R of the the saturable absorption mirror is set to a value not less than 0.4%, and the absolute value |D| (D<0) of a total intracavity dispersion amount D when light having a predetermined wavelength makes one round trip in the resonator, which is represented by the following relational expression, is set within a pulse bandwidth in which operation modes other than a fundamental period soliton pulse can be suppressed by the saturable absorption mirror. ? P = 1.

Abstract: Two end facets of a solid state laser medium function as resonating mirrors that cause a pumping light beam to resonate within the solid state laser medium, which becomes a resonator. A pumping means outputs the pumping light beam, having at least two longitudinal modes and a coherence length greater than or equal to the resonator length of the resonator, to be input to the solid state laser medium such that the laser beam resonates within the resonator.

Abstract: There is provided a mode locked laser device including: a cavity, the cavity having a semiconductor saturable absorbing mirror and a negative dispersion mirror that controls group velocity dispersion within the cavity, disposed in a straight line; a solid-state laser medium, disposed in the cavity and outputting oscillating light due to excitation light being incident thereon; an excitation unit that causes the excitation light to be incident on the solid-state laser medium; and a cavity holder, the light incident face of the semiconductor saturable absorbing mirror attached to one end of the cavity holder, the negative dispersion mirror attached to the other end of the cavity holder, and the cavity holder integrally supporting the semiconductor saturable absorbing mirror and the negative dispersion mirror.

Abstract: A photoacoustic imaging apparatus is equipped with: light generating means, for emitting measuring light; light irradiating means, for irradiating the measuring light onto a target; ultrasound detecting means, for detecting ultrasonic waves which are generated in the target portion by the irradiation of the measuring light; and tomographic image obtaining means, for obtaining a tomographic image of the target based on signals of the detected ultrasonic waves. The light generating means includes a pulse laser and light modulating means, which are employed to emit a pulse train having a plurality of pulse beams having pulse widths within a range from 1 nsec to 100 nsec as the measuring light. The tomographic image obtaining means generates processed signals by performing a correlating process between transmission signals of the pulse train and the signals of the ultrasonic waves, and obtains the tomographic image of the target based on the processed signals.

Abstract: In a mode-locked laser-diode-excited laser apparatus: a solid-state laser medium is arranged at a distance of at most twice the Rayleigh range from a saturable absorbing mirror with a depth of absorbing modulation of at least 0.4%; the total intracavity dispersion is smaller than zero and makes oscillating light have such a pulse bandwidth that the saturable absorbing mirror can suppress a background pulses other than soliton pulses repeated with a fundamental repetition period, and the magnitude of the total intracavity dispersion has a predetermined relationship with a pulse width of the oscillating light; and an output mirror is a negative-dispersion mirror being constituted by two multilayer mirrors and a cavity layer sandwiched between the two multilayer mirrors, and causing a mirror dispersion of ?3000 fsec2 to ?600 fsec2 and realizes a reflectance of 97% to 99.5%.

Abstract: In a mode-locked laser-diode-excited laser apparatus: a solid-state laser medium is arranged at a distance of at most twice the Rayleigh range from a saturable absorbing mirror with a depth of absorbing modulation of at least 0.4%; the total intracavity dispersion is smaller than zero and makes oscillating light have such a pulse bandwidth that the saturable absorbing mirror can suppress a background pulses other than soliton pulses repeated with a fundamental repetition period, and the magnitude of the total intracavity dispersion has a predetermined relationship with a pulse width of the oscillating light; and an output mirror is a negative-dispersion mirror in which high-index layers and low-index layers, having optical thicknesses randomly varying in the range of one-eighth to half of the predetermined wavelength, are alternately laminated, and the negative-dispersion mirror causes a mirror dispersion of ?1000 fsec2 to ?100 fsec2 and realizes a reflectance of 97% to 99.5%.

Abstract: In a mode-locked laser-diode-excited laser apparatus: a solid-state laser medium is arranged at a distance of at most twice the Rayleigh range from a saturable absorbing mirror with a depth of absorbing modulation of at least 0.4%; the total intracavity dispersion is smaller than zero and makes oscillating light have such a pulse bandwidth that the saturable absorbing mirror can suppress a background pulses other than soliton pulses repeated with a fundamental repetition period, and the magnitude of the total intracavity dispersion has a predetermined relationship with a pulse width of the oscillating light; and an output mirror is a negative-dispersion mirror being constituted by three or more multilayer mirrors and cavity layers arranged at predetermined intervals between the three or more multilayer mirrors, and causing a mirror dispersion of ?3000 fsec2 to ?600 fsec2 and realizes a reflectance of 97% to 99.5%.

Abstract: A mode-locked solid-state laser apparatus having a resonator which includes a solid-state laser medium, a saturable absorption mirror, and a negative group dispersion element therein, in which the solid-state laser medium and the saturable absorption mirror are disposed at a distance not greater than twice a Rayleigh length which is determined by the beam radius of oscillation light formed at the saturable absorption mirror. The apparatus further includes a dichroic mirror in the resonator that reflects excitation light inputted from a direction crossing the optical axis of the resonator toward the solid-state laser medium and transmits oscillation light.

Abstract: In a soliton mode-locked solid-state laser apparatus having a resonator which includes therein a solid-state laser medium, a saturable absorption mirror, and a negative group velocity dispersion element, the solid-state laser medium and saturable absorption mirror are disposed in close proximity to each other at a distance not greater than twice a Rayleigh length. Then, the absorption modulation depth ?R of the the saturable absorption mirror is set to a value not less than 0.4%, and the absolute value |D|(D<0) of a total intracavity dispersion amount D when light having a predetermined wavelength makes one round trip in the resonator, which is represented by the following relational expression, is set within a pulse bandwidth in which operation modes other than a fundamental period soliton pulse can be suppressed by the saturable absorption mirror. ? P = 1.

Abstract: In a mirror including a substrate and a dielectric multilayer coating structure formed on the substrate, the multilayer coating structure includes two mirror-function layer portions, each formed by a plurality of Layers deposited one on another, and a cavity layer that is arranged between the two mirror-function layer portions, and which causes light having a predetermined wavelength to resonate between the two mirror-function layer portions. Further, a dispersion value with respect to the light having the predetermined wavelength is in the range of ?600 fs2 to ?3000 fs2 and a reflectance with respect to the light having the predetermined wavelength is in the range of 97% to 99.5%.

Abstract: A dispersion compensator which is compact, low loss, low cost, and highly stable, and yet capable of varying the dispersion compensation amount without changing the output position of an output beam. The dispersion compensator includes: a first and a second planar mirrors disposed parallel to each other, wherein at least either one of the mirrors has group velocity dispersion whose value varies according to the incident angle of light incident on the mirror; a mirror holding means rotatably holding the first and second mirrors in a direction in which the incident angle of light incident on the first mirror is changed while maintaining the parallel state of the mirrors; and a third mirror disposed so as not to be rotated with the first and second mirrors and reflects light reflected sequentially by the first mirror and the second mirror.