The present invention provides a spectral apparatus for spectrally separating light including a predetermined wavelength, including a slit that the light enters, a first optical system configured to collimate the light from the slit, a transmissive type diffraction element configured to diffract the light from the first optical system, and a second optical system including a first mirror configured to reflect the light diffracted by the transmissive type diffraction element, and a second mirror configured to reflect the light reflected by the first mirror and diffracted by the transmissive type diffraction element, and configured to make the light reciprocally travel between the first mirror and the second mirror via the transmissive type diffraction element.

A spectrum measurement device includes a scanning light receiver, an optical component, and a processor. The scanning light receiver, on a plane, receives a plurality of light beams of a display image sequentially according to a scanning operation to generate a plurality of input light beams sequentially. The optical component receives the input light beams sequentially and generates a plurality of pieces of processed information. The processor obtains luminance and chromaticity information of the display image according to the processed information.

Apparatuses, systems, and methods for Raman spectroscopy are described. In certain implementations, a spectrometer is provided. The spectrometer may include a plurality of optical elements, comprising an entrance aperture, a collimating element, a volume phase holographic grating, a focusing element, and a detector array. The plurality of optical elements are configured to transfer the light beam from the entrance aperture to the detector array with a high transfer efficiency over a preselected spectral band.

A light source apparatus includes an optical amplifier, a spectroscopic element, a spatial phase modulating element, and a controller. The spectroscopic element separates light from the optical amplifier according to wavelengths. The spatial phase modulating element includes a base part and a plurality of grating elements that reflect the light separated by the spectroscopic element. The spatial phase modulating element relatively displaces at least a part of grating elements with respect to the base part and thereby performs phase modulation on the light separated by the spectroscopic element, and emits diffracted light along an incident optical path from the spectroscopic element regarding a part of the wavelengths. The diffracted light generates the light having the part of the wavelengths in the spectroscopic element. The light having the part of the wavelengths subjected to a plurality of times of amplification by the optical amplifier is output.

A monolithic, fully-immersed spectrometer using crossed cylindrical lenses enables independent focusing of the incoming beam along the two principal axes, e.g. x-axis and y-axis, perpendicular to the optical axis. A first lens flattens the beam before entering the body of a second curved, reflective lens, so the second lens only needs to focus in one axis. This restricts the curvature to 1-dimension and therefore reduces the thickness of the device by an order of magnitude compared to a design based on spherical lenses. A cylindrical-based design greatly increases manufacturability and scalability.