Pulsed laser with repetition rate of 57.8 GHz

Graphene(Gf) was synthesized directly on the surface of a Cu wire that acted as a hub for diameter-controlled micro-fibers(DCMFs) to form the ring resonator. The Gf layer physically contacted with the DCMFs for the nonlinear interaction with fully minimized damage. Conventional Gf mode-locking scheme without a ring resonator is compared with the proposed scheme. Also, scalability toward multichannel operation is described. Credit: Korea Institute of Science and Technology (KIST)

The Korea Institute of Science and Technology (KIST) announced that the research team at the Center for Opto-Electronic Materials and Devices was able to generate laser pulses at a rate at least 10,000 times higher than the state of the art.

This achievement was accomplished by inserting an additional resonator containing graphene into a fiber-optic pulsed-laser oscillator that operates in the domain of femtoseconds (10-15 seconds). The data transmission and processing speeds are expected to increase significantly by applying this method to data communications.

The KIST research team noted that the characteristics of the wavelength and intensity of laser light that change over time are correlated (Fourier transform). If a resonator is inserted into the laser oscillator, the wavelength of the pulsed laser is periodically filtered, thereby modifying the pattern of laser intensity change. This allows the laser intensity change to be accurately controlled at a high rate, and thus the repetition rate of pulses could be increased to a higher level.

As a result, it was possible to obtain a repetition rate of 57.8 GHz, thereby overcoming the limitations of pulsed lasers in terms of repetition rate, typically constrained to MHz. (Phys.org)

The paper has been published in ACS Nano.

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