Science Daily March 22, 2023
Mechanical frequency combs are poised to bring the applications and utility of optical frequency combs into the mechanical domain. So far, their main challenge has been strict requirements on drive frequencies and power, which complicate operation. An international team of researchers (the Netherlands, USA – NIST) has demonstrated a straightforward mechanism to create a frequency comb consisting of mechanical overtones (integer multiples) of a single eigenfrequency, by monolithically integrating a suspended dielectric membrane with a counter-propagating optical trap. The periodic optical field modulated the dielectrophoretic force on the membrane at the overtones of a membrane’s motion. These overtones shared a fixed frequency and phase relation, and constituted a mechanical frequency comb. The periodic optical field also created an optothermal parametric drive that required no additional power or external frequency reference. This combination of effects resulted in an easy-to-use mechanical frequency comb platform that required no precise alignment, no additional feedback or control electronics, and only used a single, mW continuous wave laser beam. According to the researchers this highlights the overtone frequency comb as the straightforward future for applications in sensing, metrology and quantum acoustics… read more. Open Access TECHNICAL ARTICLE
Schematic of overtone frequency comb. Credit: Nature Communications volume 14, Article number: 1458 (2023)Â