Zero-PDG silicon photonic amplifier with high saturation power and low noise figure

Abstract

Abstract High-power amplifiers are of great importance in many optical systems deployed in optical sensing, ranging, medical surgery and more. Likewise, high-gain, low-noise amplifiers with low polarization dependence are critical components of long-range optical communication systems. Integrated photonic solutions show great potential in challenging application fields thanks to their drastic reduction in size, weight and cost, but coming at the expense of low optical power due to reduced energy storage capacity in small devices. Recently, the large mode area (LMA) technology, which is known for dramatically increasing the energy storage capacity and saturation power of fiber amplifiers, has been brought to the chip-level, allowing for watt-level amplification directly from the chip. Here we demonstrate a silicon photonic LMA amplifier capable of both high-power amplification with output saturation powers > 115 mW and high small-signal gain up to 30 dB with a 3.6 dB noise figure on-chip, which we achieved by suppressing parasitic lasing with index-matching glue on the chip facets. Furthermore, we present a method to tune and completely nullify the polarization dependent gain (PDG). We believe that the PDG-tunability combined with the low-noise, high-gain and high-power amplification positions it as a potentially disruptive technology for next-generation integrated amplifiers across a range of applications.