A method of processing two dimensional optical spectra, such as echelle spectra, is disclosed. The optical spectra comprise sections having a relatively high intensity separated by borders having a relatively low intensity. The optical spectra have been digitized (61) by a detector. The method comprises denoising (62) an optical spectrum, searching (64) for at least one series of neighboring local extrema of the optical spectrum, fitting (65) a line through each series of neighboring local extrema, each line representing a section, identifying (67) any peaks and their respective locations, and storing (68) the lines and the locations of any peaks.

Configurations for light source modules and methods for mitigating coherent noise are disclosed. The light source modules may include multiple light source sets, each of which may include multiple light sources. The light emitted by the light sources may be different wavelengths or the same wavelength depending on whether the light source module is providing redundancy of light sources, increased power, coherent noise mitigation, and/or detector mitigation. In some examples, the light source may emit light to a coupler or a multiplexer, which may then be transmitted to one or more multiplexers. In some examples, the light source modules provide one light output and in other examples, the light source modules provide two light outputs. The light source modules may provide light with approximately zero loss and the wavelengths of light may be close enough to spectroscopically equivalent respect to a sample and far enough apart to provide coherent noise mitigation.

A spectrometer with a Schmidt reflector is described. The spectrometer may include a Schmidt corrector and a dispersive element as separate components. Alternatively, the Schmidt corrector and dispersive element may be combined into a single optical component. The spectrometer may further include a field-flattener lens.

Configurations for a diffraction grating design and methods thereof are disclosed. The diffraction grating system can include an input waveguide located at a first location on or near a Rowland circle and multiple output waveguides located at a second and third location on or near the Rowland circle. The input waveguide may be located between the output waveguides and this configuration of input and output waveguides can reduce the footprint size of the device. In some examples, the optical component can function as a de-multiplexer. Additionally, the optical component may separate the input wavelength band into two output wavelength bands which are separated from one another by approximately 0.1 μm.

A multipulse-induced spectroscopy method based on a femtosecond plasma grating includes: pre-exciting a sample on a stage by providing a femtosecond pulse to form the femtosecond plasma grating; providing a post-pulse on the sample at an angle to excite the sample to generate a plasma, wherein the post-pulse comprises one or more femtosecond pulses, there is a time interval between the femtosecond pulse and the post-pulse, and the time interval is less than a lifetime of the femtosecond plasma grating; and receiving and analyzing a fluorescence emitted from the plasma to determine element information of the sample.

An apparatus and a method for shaping a light spectrum are presented. The apparatus includes a spatial light modulator (140) provided for shaping the spectrum of a primary beam. The spatial light modulator (140) includes an array of cells in which each cell is operable in a first state and a second state. The apparatus also includes a controller (160) configured to change the state of a subset of cells iteratively, based on a stochastic process, to shape the spectrum.

Spectrometers include an optical assembly with optical elements arranged to receive light from a light source and direct the light along a light path to a multi-element detector, dispersing light of different wavelengths to different spatial locations on the multi-element detector. The optical assembly includes: (i) a collimator arranged in the light path to receive the light from the light source, the collimator including a mirror having a freeform surface; (2) a dispersive sub-assembly including an echelle grating, the dispersive sub-assembly being arranged in the light path to receive light from the collimator; and (3) a Schmidt telescope arranged in the light path to receive light from the dispersive sub-assembly and focus the light to a field, the multi-element detector being arranged at the field.

Systems, devices, and methods of analyzing an interfered peak of a sample spectrum is disclosed. The sample spectrum may be generated using a detector of an optical spectrometer. The interfered peak may be produced by a plurality of spectral peaks of different wavelengths. The method may include generating interfered curve parameters representative of the peak shape of each spectral emission in the interfered peak based at least in part on a model of expected curve parameters for the optical spectrometer and a location of the interfered peak on the detector of the optical spectrometer; fitting a plurality of curves to the interfered peak, each curve corresponding to one of the plurality of spectral emissions of different wavelengths forming the interfered peak, wherein each curve is fitted using the interfered curve parameters provided by the model of expected peak parameters; and outputting the plurality of curves for further analysis.

A tunable ultra-compact spectrometer and methods for spectrometry therefor can include a single pixel and a Fresnel zone plate having a focal length at a first temperature T.sub.1 and a first wavelength λ.sub.1, and a focal point. The pixel can be twenty micrometers square and can be placed at a distance from the pixel that equal to the focal length so that the focal point is at the pixel. The Fresnel zone plate can be made of a material that causes the same focal point at the pixel at T.sub.2, but at a different wavelength λ.sub.2 than wavelength λ.sub.1. A heat source can selectively add heat to the Fresnel zone plate to cause a second temperature T.sub.2. Exemplary materials for the Fresnel zone plate can be quartz for visible wavelengths, silicon for infrared wavelength, or other materials, according to the λ(s) of interest.

A spectrograph that includes camera focusing optics with a primary mirror having a concave-shaped reflective mirror surface, a secondary mirror having a convex-shaped reflective mirror surface and positioned to receive light reflected by the primary mirror, a tertiary mirror having a concave reflective mirror surface and positioned to receive light reflected by the secondary mirror, and a field correcting lens comprising a convex lens surface in combination with a concave lens surface, wherein light received by said field correcting lens from said tertiary mirror enters said convex lens surface, traverses said field correcting lens, and exits from said concave lens surface. The optional field correcting lens is positioned such that the primary mirror, secondary mirror, tertiary mirror, and the field correcting lens share the common parent vertex axis.