A method of calibrating a spectrophotometer comprising a flash lamp. The method comprises receiving light from the flash lamp at a monochromator of the spectrometer, wherein the flash lamp is a short arc noble gas flash lamp with transverse or axially aligned electrodes; configuring the monochromator to progressively transmit the received light at each of a plurality wavelengths of a selected range of wavelengths, wherein the range of wavelengths is associated with a wavelength feature according to a known spectral profile of the flash lamp, and wherein the wavelength feature is a self-absorption feature; and determining a spectrum of the flash lamp, wherein the spectrum comprises a corresponding power or intensity value for each of the plurality of wavelengths. The method further comprises determining a wavelength calibration error value for the wavelength feature by comparing the spectrum with a segment of a predetermined reference spectrum associated with the flash lamp, wherein the segment of the predetermined reference spectrum includes one or more wavelengths associated with the self-absorption feature; and calibrating the spectrophotometer based on the wavelength calibration error value.

A method of calibrating a spectrophotometer comprising a flash lamp. The method comprises receiving light from the flash lamp at a monochromator of the spectrometer, wherein the flash lamp is a short arc noble gas flash lamp with transverse or axially aligned electrodes; configuring the monochromator to progressively transmit the received light at each of a plurality wavelengths N of a selected range of wavelengths, wherein the range of wavelengths is associated with a wavelength feature according to a known spectral profile of the flash lamp, and wherein the wavelength feature is a self-absorption feature; and determining a spectrum of the flash lamp, wherein the spectrum comprises a corresponding power or intensity value for each of the plurality of wavelengths. The method further comprises determining a wavelength calibration error value for the wavelength feature by comparing the spectrum with a segment of a predetermined reference spectrum associated with the flash lamp, wherein the segment of the predetermined reference

A stray light reducing apparatus includes a light source and an entrance slit positioned to pass through light from the light source. A first monochromator mirror is positioned to reflect light passed through the entrance slit. A diffractive surface is positioned to receive and diffract light reflected by the first monochromator mirror. A second monochromator mirror is positioned to reflect light diffracted by the diffractive surface. An exit slit is positioned to pass through light reflected by the second monochromator mirror. A cuvette is positioned to pass through light passed through the exit slit. A long-pass interference filter is positioned to receive light from the light source, reflect light that has a wavelength below a selected value, and pass through light having a wavelength above the selected value. A first sample detector is positioned to receive light reflected by the long-pass interference filter.

An interlaced diffraction grating system and process are disclosed. The interlaced grating system includes an optical dispersive grating with alternating bands of unique grating densities wherein the number of unique grating densities is greater than or equal to two. The optical dispersive grating may be reflective or transmissive, and it may be fabricated by mechanical ruling, holography, or reactive ion etching of a binary mask. An interlaced grating allows additional utility for both point spectroscopic detection as well as hyperspectral imaging.

An interlaced diffraction grating system and process are disclosed. The interlaced grating system includes an optical dispersive grating with alternating bands of unique grating densities wherein the number of unique grating densities is greater than or equal to two. The optical dispersive grating may be reflective or transmissive, and it may be fabricated by mechanical ruling, holography, or reactive ion etching of a binary mask. An interlaced grating allows additional utility for both point spectroscopic detection as well as hyperspectral imaging.

A stray light reducing apparatus includes a light source and an entrance slit positioned to pass through light from the light source. A first monochromator mirror is positioned to reflect light passed through the entrance slit. A diffractive surface is positioned to receive and diffract light reflected by the first monochromator mirror. A second monochromator mirror is positioned to reflect light diffracted by the diffractive surface. An exit slit is positioned to pass through light reflected by the second monochromator mirror. A cuvette is positioned to pass through light passed through the exit slit. A long-pass interference filter is positioned to receive light from the light source, reflect light that has a wavelength below a selected value, and pass through light having a wavelength above the selected value. A first sample detector is positioned to receive light reflected by the long-pass interference filter.