Broadband Spectral Splitting of Light Using Wavefront Shaping


Gün B. N. , Yüce E.

20. Ulusal Optik, Elektro-Optik ve Fotonik Çalıştayı, Ankara, Turkey, 14 September 2018, pp.88

  • Publication Type: Conference Paper / Summary Text
  • City: Ankara
  • Country: Turkey
  • Page Numbers: pp.88

Abstract

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].