Research Information System
20. Ulusal Optik, Elektro-Optik ve Fotonik Çalıştayı, Ankara, Turkey, 14 September 2018, pp.88
When the dimensions of a medium are comparable to wavelength of light, diffraction plays a major role in wave
propagation and it differs by wavelength. Thus, it is possible to obtain intended phase difference for each frequency by
changing the thickness or refractive index of the medium [1]. As a result, waves at a specific frequency can be controlled
to constructively interfere at a desired point. Liquid crystal displays, which enable to control refractive indices of each
pixels via modulating the amplitude of the applied electric field can be used to control diffraction. By this programmable
control, the spatial phase of light can be changed between 0-2π and the phase pattern for spectral splitting can be
determined [2]. Our theoretical results show that spectral splitting is achieved with total efficiency of more than 70%
when we focus two different wavelengths to two different regions. In addition, for non-moving sources the total relative
intensity of 400 nm light focuses properly to a region by 45%, and by 30% at 0.004° incidence angle [3].