Computer Generated Hologram for Beam Control of LCOS based Wavelength Selective Switch
This paper presents the design of a computer generated hologram for beam control of an LCOS based wavelength selective switch, which is the core technology for next generation ROADM. By introducing a computer generated hologram instead of general grating patterns to control the LCOS device, we contribute to building a more efficient wavelength selective switch. With the use of phase modulation properties of LCOS devices, we designed the hologram for five port output and a 40 channel wavelength selective switch. We applied a multi level phase modulation technique with the Gerchberg Saxton algorithm to produce the hologram, which is easily scalable to any different type of wavelength selective switch. With an experimental setup, we verified the usability of the hologram designed for five port output. We also suggest a hologram design technique for beam control of a 40 channel wavelength selective switch.