Digital optical spectrometer-on-chip

A concept of digital optical spectrometer-on-chip is proposed and results of their fabrication and characterization are reported. The devices are based on computer-designed digital planar holograms which involves millions of lines specifically located and oriented in order to direct output light into designed focal points according to the wavelength. Spectrometers were fabricated on silicon dioxide and hafnium dioxide planar waveguides using electron beam lithography and dry etching. Optical performances of devices with up to 1000 channels for a central wavelength of 660 nm are reported.