Coherent terahertz radiation with 2.8-octave tunability through chip-scale photomixed microresonator optical parametric oscillation

Abstract

High-spectral-purity frequency-agile room-temperature sources in the terahertz spectrum are foundational elements for imaging, sensing, metrology, and communications. Here we present a chip-scale optical parametric oscillator based on an integrated nonlinear microresonator that provides broadly tunable single-frequency and multi-frequency oscillators in the terahertz regime. Through optical-to-terahertz down-conversion using a plasmonic nanoantenna array, coherent terahertz radiation spanning 2.8-octaves is achieved from 330 GHz to 2.3 THz, with ≈20 GHz cavity-mode-limited frequency tuning step and ≈10 MHz intracavity-mode continuous frequency tuning range at each step. By controlling the microresonator intracavity power and pump-resonance detuning, tunable multi-frequency terahertz oscillators are also realized. Furthermore, by stabilizing the microresonator pump power and wavelength, sub-100 Hz linewidth of the terahertz radiation with 10−15 residual frequency instability is demonstrated. The room-temperature generation of both single-frequency, frequency-agile terahertz radiation and multi-frequency terahertz oscillators in the chip-scale platform offers unique capabilities in metrology, sensing, imaging and communications.

Brillouin laser-driven terahertz oscillator up to 3 THz with femtosecond jitter

“…We compare the timing noise at 300 GHz with other state-of-the-art sources between 300 -1000 GHz in Fig. 3 [15,17,19,21,[41][42][43][44]. Note that most of the oscillators in this comparison have no clear path for implementing wide tunability.…”

“…Regardless, the measured timing noise level is below 1 fs/ √ Hz for Fourier frequency exceeding 300 Hz at all carrier frequencies from 300 GHz to 3 THz. The This work [15] @ 300 GHz [41] @ 670 GHz [19] @ 560 Ghz [17] @ 300 GHz [44] @ 651 GHz [42] @ 1 THz…”

Interference Picture Ring System of Coherent Oscillators

“…В теории антенн для анализа характеристик направленности излучения используется метод векторных диаграмм, позволяющий изучить физические свойства, получить аналитическое решение, описанный, в частности, в [5,6]. Использование других конфигураций [7] позволяет решать другие проблемы измерительной и телекоммуникационной техники [8][9][10]. Для обеспечения широкоугольного сканирования используют выпуклые (сферические, цилиндрические, конические) и другие геометрические поверхности, обеспечивающие диапазонную работу антенных решеток [7].…”