Researchers at NIST’s Center for Nanoscale Science and Technology have developed a low-noise optical wavelength converter using nanofabricated waveguides on a silicon platform. This device can change the wavelength of light without adding extra noise, which is crucial for many applications in classical and quantum information processing.
The wavelength converter uses silicon nitride waveguides on a silicon substrate, designed through electromagnetic simulations. It employs a process called four-wave-mixing Bragg scattering, where an input signal is converted to an output field with a frequency shift determined by the difference in frequencies of two applied pump fields.
The new device achieves conversion efficiencies of a few percent, approaching levels needed for some applications, with no added noise. It is much smaller than previous solutions using nonlinear crystals or optical fibers, and can be integrated with other on-chip devices using scalable silicon-based fabrication methods.
Future work will focus on increasing conversion efficiency by optimizing waveguide geometry and incorporating waveguides into optical resonators.
Keywords: Nanofabricated, Silicon-based, Waveguides, Frequency converters, Silicon nitride
