A photonic frequency discriminator based on a two wavelength delayed self-heterodyne interferometer for low phase noise tunable micro/mm wave synthesis

Abstract

Low phase noise frequency synthesizers are of paramount interest in many areas of micro-mm wave technology, encompassing for example advanced wireless communication, radar, radio-astronomy, and precision instrumentation. Although this broad research field is not bereft of methods for the generation of either low phase noise micro- or mm waves, no universal system applicable to low phase noise generation for micro and mm waves has yet been demonstrated. Here we propose a new photonic frequency discriminator based on a two wavelength delayed self-heterodyne interferometer which is compatible with such an objective. The photonic frequency discriminator can be a reference both for micro and mm waves to lower their phase noise. As a proof-of-concept, we demonstrate a low phase noise tunable OEO (6–18 GHz) and locking of a heterodyne beat between two cw lasers (10–400 GHz) with low relative phase noise. The required components for the photonic frequency discriminator are off-the-shelf and can be readily assembled. We believe this new type of photonic frequency discriminator will enable a new generation of universal precision tunable sources for the X, K, V, W and mm-bands and beyond.

Low phase noise THz generation from a fiber-referenced Kerr microresonator soliton comb

“…However, fiber combs and solid-state laser combs cannot be applied to the generation of mm and THz waves owing to the inherently narrow comb mode spacings (< 1 GHz). On the other hand, other photonics-based methods such as optoelectronic oscillators (OEOs) [14,15] and heterodyning of two CW lasers [16][17][18][19][20] are suitable for the generation of mm and THz waves. In particular, heterodyne methods can be easily applied to a higher frequency.…”

“…Also, two narrow-linewidth CW lasers are required in addition to the Kerr comb. Another method to stabilize the f rep of Kerr combs is based on a two-wavelength delayed self-heterodyne interferometer (TWDI) [18,[27][28][29], in which a long fiber in an imbalanced Mach-Zehnder interferometer (i-MZI) works as a reference. In the method, the phase noise of the f rep is measured in a self-referencing way owing to the time delay between the two arms in the i-MZI, allowing simple and robust operation of the stabilization system.…”

Amplification and phase noise transfer of a Kerr microresonator soliton comb for low phase noise THz generation with a high signal-to-noise ratio

“…s−s is measured by a two-wavelength delayed selfheterodyne interferometer (TWDI) (Fig. 1(b)) [22,23]. The TWDI consists of an imbalanced Mach-Zehnder interferometer (i-MZI) with an acousto-optic modulator (AOM) in one of the arms for the heterodyne measurement.…”

Refined method to extract frequency-noise components of lasers by delayed self-heterodyne

“…In the last decades, the DSH method [28] has risen to this challenge and has become a standard approach [29] with refinements of the method continuously being reported [30][31][32][33][34]. An alternative approach relies on measuring the FN PSD of the light source.…”