New Optical Amplifier Generates More Light in a Smaller Footprint

Graphic representation of optical signals propagating through a USRN waveguide undergoing 42.5dB of optical parametric amplification. (Image courtesy of Dawn Tan.)
Photonics researchers have developed an optical amplifier that amplifies light by up to 17,000 times at telecommunications wavelengths. In addition, it can be produced at low cost and is small enough to be placed on a chip.

When used within an optical interconnect, such as a transceiver or fiber optic network, the amplifier increases the power of the transmitted light before it is completely depleted through optical losses.

The compact, high gain amplifier shows promise for highly efficient nonlinear optics applications, particularly in the field of CMOS photonics, as well as precision manufacturing and hyperspectral imaging. The amplifier can also be used as a tunable broadband light source, enabling cheaper and more efficient spectroscopic sensing and molecular fingerprinting.

As a bonus, the amplifier’s diminished size comes with a diminished cost. A conventional optical amplifier costs several hundred thousand dollars, and occupies an entire optical table, while the newly developed amplifier is smaller than a paperclip and costs a fraction of that price.


Building a Better Light Amplifier

 "We use a proprietary platform called ultra-silicon-rich nitride, with a material composition of seven parts silicon, three parts nitrogen, with the large nonlinearity and photon efficiency needed for high gain amplification, through the efficient transfer of photons from a pump to the signal,” explained assistant professor Dawn Tan of the Singapore University of Technology and Design (SUTD), who led the development of the device.

"The inefficiencies in highly nonlinear photonic devices are overcome here, by photonic device engineering for maximum nonlinearity, while still maintaining a sufficiently large bandgap to eliminate two-photon absorption at the telecommunications wavelength. We believe this is one of the highest gains demonstrated at the telecommunications wavelength to date on a CMOS chip" said Tan.

Development of the amplifier was a collaborative effort between researchers at SUTD, A*STAR Data Storage Institute and MIT.

The research is published in the journal Nature Communications.