Acousto-optic spectrometer for speckle imaging

We report on the acousto-optic spectral imaging system designed for speckle imaging observations and interferometry. The setup is based on a non-collinear paratellurite acousto-optic tunable filter (AOTF). Breadboard prototype of the system with an in-house fabricated AOTF has been designed and commissioned. The prototype spectral range covers the band from 3600 to 5800 Å. Arbitrary spectral transmission function synthesis of the AOTF was applied. The AOTF spectral transmission bandwidth is programmable in the range from 44 to 875 cm⁻¹ (12.5–250Å at the wavelength of 5050Å). The AOTF is synchronized with the CCD readout and can be used as a global electronic shutter with on/off switching time of 12 μs. The exposure is adjusted as any integer multiple of 4.5 μs.