MyntOptics Engineering Tools
Tools / Spectroscopy

Grating Spectrometer Designer

First-order design of a plane-grating spectrometer from the grating equation mλG = sin α + sin β, with the real-world slit-limited instrument bandpass, étendue/throughput and order overlap. The achievable resolution is the convolution of the imaged slit width, the pixel and the grating limit.

Grating & geometry

gr/mm
–
deg
mm
mm

Spectral band & detector

nm
nm
nm
px
µm
µm
mm
The detector is centered on the chief diffracted ray at λc; positions map as x(λ) = f·tan(β − β_c). The slit is imaged onto the detector at the anamorphic magnification (fcam/fcoll)·(cos α/cos β).

Design summary

Instrument bandpass & throughput advanced

What this means

Diffraction geometry at λc

Diffraction angle vs wavelength (orders m−1, m, m+1)

Detector mapping & order overlap

Order overlap: light at wavelength λ′ = mλ/(m±1) from adjacent orders lands at the same detector position as λ in order m. If a neighboring-order curve crosses the detector window within your source band, you need order-sorting filters.