Design of a digital tunable stellar spectrum calibration source based on a digital micromirror device

Abstract

A design method of spectral tunable radiation source with supercontinuum laser as the radiation source and digital micro-mirror device (DMD) as the spectral modulation device is proposed. Adopt the design idea of reducing the relative aperture of the spectral imaging system to improve the imaging quality, use cylindrical collimating beam expanding system to replace the collimating objective in the traditional spectral imaging system, and the relative aperture of the system is reduced in the dispersion direction. According to the test results, in narrow-band mode, the maximum full width at half maximum (FWHM) of monochromatic light bandwidth in the spectrum range of 450–1000 nm is 3.86 nm. In the broad-band mode, four typical stellar color temperature of T = 2600 K, 3500 K, 7000 K, 11,000 K are simulated, and the simulation results show that the accuracy of the star spectrum is better than 3.1% at 2600 K, 4.2% at 3500 K, 2.8% at 7000 K and 5.1% at 11,000 K.