• Physics 15, s159
Experiments disprove the overall assumption that a couple of wave mode is required to supply a spectral sample referred to as a frequency comb.
Frequency combs—units of sharp, equally spaced spectral traces—have revolutionized metrology. Specifically, they’ve led to extremely correct time and distance measurements. Standard knowledge means that making a frequency comb requires coupling not less than two wave modes of a system. However Jana Ochs on the College of Konstanz, Germany, and her colleagues have now demonstrated a comb that wants just one such mode . This property provides the comb benefits together with an simply adjustable construction and a low required energy.
Frequency combs are usually produced utilizing mild, however they can be generated utilizing mechanical vibrations, such that every spectral line corresponds to a special vibrational frequency. Not like optical combs, these so-called phononic combs may be tuned in situ. Till now, they’ve been created by means of a nonlinear coupling of two or extra modes of vibration.
Ochs and her colleagues carried out experiments on a tiny, vibrating system often called a nanomechanical resonator. This system reveals a single vibrational mode that’s excited by a periodically utilized exterior driving power. The low-frequency oscillations within the amplitude and part of this pushed mode are extremely nonlinear. These oscillations modulate the system’s vibration, giving rise to a phononic comb.
The researchers discovered that they may management the quantity and spacing of the comb’s spectral traces by adjusting the frequency and energy of the driving power. They are saying that their experiments present perception into the character of frequency combs and reveal a brand new mechanism for producing such combs. Nonetheless, the staff stresses that extra work is required to completely perceive how this mechanism works.
Ryan Wilkinson is a Corresponding Editor for Physics Journal primarily based in Durham, UK.
- J. S. Ochs et al., “Frequency comb from a single pushed nonlinear nanomechanical mode,” Phys. Rev. X 12, 041019 (2022).