Higher signal processing possible by ultra-strong squeezing of light
Researchers in Singapore have developed a temporal compression system that demonstrates the ability to squeeze light in time by 11X.
A team from the Singapore University of Technology and Design (SUTD), in conjunction with the A*STAR Institute of Microelectronics (Singapore) and the Massachusetts Institute of Technology (MIT; Cambridge, MA), developed the system, which essentially allows “an equivalent increase in the number of bits transmitted by light in a fiber-optic network.” As the new system is ultra-small, it has been able to provide a several-orders-of-magnitude smaller footprint than existing benchtop compressor systems, which are typically large and bulky, used for generating short pulses in ultrafast optical signal processing.
The system’s two-stage design that features a dispersive element and strongly nonlinear component—both integrated on the same chip—has allowed the researchers to achieve such high compression (see figure).
"By balancing the contributions from the dispersive and nonlinear stages, we could generate strong compression in either time or frequency,” says Dr. Ju Won Choi, a postdoctoral researcher in the Photonics Devices and Systems Group at SUTD who was involved with the study. “The temporal compression is one of the strongest demonstrated to-date on a chip. The spectral compression is also the first of its kind demonstrated on a chip.”
Leveraging space and time
The study found that in leveraging analogous dualities in space and time, the same system can prompt the frequency (wavelength) content of light to also be squeezed.1 For example, light that has red, yellow, and blue colors will be “spectrally compressed to only possess yellow light,” according to the researchers. So, the amount of color in an optical signal also limits the amount of data carried in a fiber optic network when wavelength-division multiplexing is used. The researchers note that in turn, spectrally squeezing the light “could allow higher spectral densities of light propagating in a specific medium.”
The team, led by principal researcher Dawn Tan, an associate professor at SUTD, showed flexibility in the manipulation of optical pulses, made possible by the on-chip integrated system’s demonstration of both high temporal and spectral compression. According to Tan, this is an “important capability as the burden on existing high-speed communications becomes more pronounced.”
“The datacenter, telecommunications, and 5G industries will require more and more capacity,” Tan says, “and approaches such as these that help squeeze more light into a given medium will aid in this drive toward faster optical communications networks."
Additionally, such strong compression of the small device footprint could aid inexpensive deployment of short pulses for telecommunications, datacenters, precision manufacturing, and hyperspectral imaging.
REFERENCE
1. J. W. Choi et al., Light Sci. Appl., 10, 130 (2021); https://doi.org/10.1038/s41377-021-00572-z.
Justine Murphy | Multimedia Director, Digital Infrastructure
Justine Murphy is the multimedia director for Endeavor Business Media's Digital Infrastructure Group. She is a multiple award-winning writer and editor with more 20 years of experience in newspaper publishing as well as public relations, marketing, and communications. For nearly 10 years, she has covered all facets of the optics and photonics industry as an editor, writer, web news anchor, and podcast host for an internationally reaching magazine publishing company. Her work has earned accolades from the New England Press Association as well as the SIIA/Jesse H. Neal Awards. She received a B.A. from the Massachusetts College of Liberal Arts.