Tools of the trade - Vol 18 - Thorlabs - #669

This line of replicated gratings is specifically designed for transmission use. Transmission gratings offer 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 provide low alignment sensitivity, minimizing alignment errors.

These blazed transmission gratings were designed for optimum performance in the visible 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.

By necessity, transmission gratings require relatively coarse groove spacings to maintain high efficiency. As the diffraction angles increase with the finer spacings, the refractive properties of the substrate 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.

■ Designed for Optimum Performance in the Visible Spectrum, Offering Different Levels of Dispersion

■ Offer a Basic Simplicity for Optical Designs that can be Beneficial in Fixed Grating Applications such as

Spectrographs

■ Offered in Many Custom Sizes on Request

Performance Comparison Various Transmission Gratings

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■ Substrate material: Schott B270

■ Thickness: 3mm nominal

■ Dimensional tolerances: ±0.5mm

■ Thickness tolerances: ±0.5mm

• 300 grooves/mm, 17.5° blaze angle

• 600 grooves/mm, 28.7° blaze angle

• 830 grooves/mm, 29.87° blaze angle

• 1200 grooves/mm, 36.9° blaze angle

600 700 800 Wavelength (nm)

THOR

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