How do VPH gratings achieve such high 1st order diffraction efficiency?
High 1st order diffraction efficiency is a key characteristic of volume phase holographic gratings (VPHGs) made using dichromated gelatin (DCG) as the holographic medium. The use of holographic techniques in their manufacture creates a sinusoidal index modulation profile, which favors diffracting light into a single order. We manufacture our own holographic recording media, which allows us to have precise control over parameters which are critical for maximizing diffraction efficiency. Building upon years of knowledge and experience, we are able to use the outstanding characteristics of DCG, such as high dynamic range and superb optical clarity across a wide spectral range, to make high performance gratings.