Highly Scalable Low Loss Fast Tuned True Time Delay Module Based on Dispersion Enhanced Photonic Crystal Fibers

To provide DARPA with an x-band >8 bits optical true time delay (TTD) module exhibiting <3dB insertion loss and <10 micro-seconds reconfiguration time, Omega Optics proposed and demonstrated a 3-dB insertion loss TTD module based on dispersion enhanced photonic crystal fiber (PCF) in conjunction with a fast wavelength tunable laser in the phase I program. For Phase II program, Omega Optics will continue with the innovation to achieve the program goals narrated in the SB042-033 solicitation. Various photonic nanostructures will be designed and simulated to generate highly dispersive PCF. The variation of opto-geometric parameters will also be investigated to evaluate the tolerance of the fabrication. The insertion loss of TTD module, which comes mostly from the coupling loss between PCF and standard single mode fiber (SMF), will be minimized to within 0.1dB per node in phase II. 4-bit (interim) and 8-bit (final) prototype TTD modules will be tested, integrated and packaged to fulfill the program goal. A tunable laser faster than 10ìs will be acquired from Agility. We will demonstrate a sparse array with a far field X-band RF pattern (main peak and its FWHM) equivalent to a 1x100 array within the phase II budget. Multiple-beam transmission and receiving functions will also be demonstrated by using the proposed multi-wavelength injection scheme. The TTD module will be suitable for future DOD research labs phased array antenna system integration.