A transmission grating offers a basic simplicity for optical designs that can be beneficial in fixed grating applications such as spectrographs. The incident light is dispersed on the opposite side of the grating at a fixed angle. Transmission gratings are very forgiving for some types of grating alignment errors.

By necessity, a transmission grating requires relatively coarse groove spacings to maintain high efficiency. As the diffraction angles increase with the finer spacings, the refractive properties of the materials used limit the transmission at the higher wavelengths and performance drops off. The grating dispersion characteristics, however, lend themselves to compact systems utilizing small detector arrays. The gratings are also relatively polarization insensitive.

Transmission Gratings: Visible & NIR

This line of blazed transmission gratings was designed for optimum performance in the visible and NIR spectrum, offering different levels of dispersion. In most cases, the efficiency is comparable to that of reflection gratings typically used in the same region of the spectrum.  Zero order data is included in all performance curves for those interested in beam splitting applications.

Transmission Gratings: UV

UV Transmission Gratings are produced on fused silica substrates providing superior diffraction efficiencies as low as 235 nm. Zero order data is included in all performance curves for those interested in beam splitting applications.

Anti-reflective Coatings

Anti-reflective coatings can be applied to the non diffracting surface of our visible Transmission gratings which increase diffraction efficiencies by reducing first surface reflection losses. Our standard AR coatings are designed to increase efficiency of the grating in the 400-800nm range. Other anti-reflection coating spectral ranges are available, contact Optometrics to discuss your specific needs.