Abstract: To provide a mode-locked pulse photoproduction filter for easily realizing self-starting mode-locking, and a laser device for generating a picosecond or femtosecond-pulse laser light by including such filter, the laser device including an amplifying unit for amplifying and outputting a light inside a resonator, and the mode-locked pulse photoproduction filter having a first filter part for selectively outputting a first wavelength component that is a wavelength component of an oscillation band inside the resonator, and a second filter part for selectively outputting a second wavelength component that is a wavelength component different from the oscillation band inside the resonator.

Abstract: The shape measurement device 1 comprises a light source 11, a measuring beam illumination system 13, a reference comb light separator 14, an optical multiplexer 15 and photodetector 16. The reference comb light separator 14 enters with a broadband light, and it separates in a reference comb light with broadband light. The frequency interval of the reference comb light changes continually depending on a size of Y-coordinate level in the image formation point, when the emission direction is assumed Z-axis direction. X-axis means a virtual cutout line for the measuring object, and Y-coordinate means depth for measuring. The interference image emerging in the detective surface is a tomogram for the measurement substantially. Using the reference comb light, the two-dimensional dislocation of depth direction is measured, wherein the dynamic range is extremely wide.

Abstract: Every depth of the measurement object measures energy structural information, refractive index, transmittance, reflectance other than property information of (as for the resolution several microns), e.g., space information at the same time. A spectrum measurement device receives a reference wave propagating in a reference path and a measurement wave propagating in a measurement path having a start point same as a start point of the reference path, and derives a spectrum of the measurement wave. The space information of the measuring object, energy structural information, refractive index, transmittance, a reflective index using spectrum measurement device are derived.

Abstract: It detects the relative phase of two measured signals using two reference signals. The relative phase detector 1 comprises reference signal generator 11, beat signal processor 12 and detecting element 13. As for reference signal generator 11, a frequency interval generates two reference signals which are the same as the frequency interval of the measured signal of two above. The beat signal processor 12 generates two beat signals from the reference signal of two measured signals and two above, and generation does the multiplication signal of these two beat signals. It removes constant decided by detection system from the DC component of the multiplication signal, and detecting element 13 detects the relative phase of two measured signals.

Abstract: The light from the light source of the wideband light is reflected by VIPA so that reflection distance varies step by step. In VIPA, the light that phase changed is generated depending on the depth of the step. A interference profile is measured by this reflected light and optical path length modulator by synthetic light with the generated optical frequency comb. The interferometer does not have a movable scanning mechanism, and the operation of the Fourier transform is unnecessary. Thus, it has the measurement of the short time. The measurement of the coaxial tomography and the one-dimensional coaxial tomography of the depth direction is possible. The measurement of the two-dimensional coaxial tomography of the depth direction is possible.