High speed fiber optic communications is an important, expensive technology in many industries. In avionics and other
fields, it is necessary to operate across a wide range of the RF spectrum. With typical systems, this would require a sperate
fiber optic communications link for each antenna being used. To remedy this, our system features a unique optical
switching system that allows for a fiber optic communications link to be connected to one of multiple RF systems to save
on hardware costs compared to existing systems.. In particular, we demonstrate a system with 3 RF inputs, but only two
fiber optic links. This is accomplished using a wavelength division multiplexing system we have designed using a
diffraction grating, in which different wavelengths of light are used. This system makes use of a mirror cavity we have
designed to reduce the device size while having the appropriate geometry such that the lasers are combined by the
diffraction grating. Each wavelength is connected to one of two detectors, which are mapped to the two wavelengths of
light. A switching system then allows for the user to choose which wavelength is directed to which RF system, where the
signal is then encoded into the intensity of the laser. These RF systems have been designed to generate a wide range of
frequencies, which are encoded in the laser via a modulation system we have designed based on a Mach-Zehnder
modulator. This modulation system includes a polarization management system, which has been designed to allow for
optimization of the polarization of light with minimal losses. This required the design of the bend radius of the fiber, as
well as the number of loops necessary to create half and quarter wave retarders. This is necessary as the modulation of the
lasers is polarization dependent.
Project Website
(Must be on UCF WIFI or VPN to access)Advisors: Dr. Peter Delfyett, Dr. Xun Gong, Dr. Sonali Das, Dr. Charles Middleton
Sponsor: Charles Middleton, Critical Frequency Design