Rapid photolithographic fabrication of high density optical interconnects using refractive index contrast polymers

Abstract

We have developed new polymer optical interconnect materials that we term refractive index contrast (RIC) polymers that are ideally suited to a wide variety of photonic interconnect applications as the refractive index can be tuned over the range of n = 1.42 to 1.56, while index contrast Δn can be precisely tuned through composition and ultraviolet exposure; the waveguides can be directly patterned in dry films with no wet or dry etching processes required. RIC polymer interconnects thus have the ability to access numerous photonic platforms, including silicon photonic chips, ion-exchange (IOX) glass optical substrates, and optical fiber arrays. We demonstrate for the first time efficient single-mode polymer interconnect fabrication via a maskless lithography approach that exhibits low loss adiabatic coupling (∼1.5dB at 1550nm) to IOX waveguides through the formation of grayscale tapers.