The terahertz (THz) frequency range, spanning from 0.1 to 10.0 THz, is a field ripe for innovation with vast, developing potential in areas like wireless communication and molecular spectroscopy. Our work introduces a dual-wavelength laser design that utilizes stimulated Brillouin scattering in an optical fibre cavity to effectively generate two highly coherent optical Stokes waves with inherently mitigated differential phase noise. To guarantee robust operation, the Stokes waves are optically injected into their respective pump lasers, which also serves to greatly improve the resulting coherence. The frequency difference between the two wavelengths is converted into THz waves through a uni-travelling-carrier photodiode. This innovative design facilitates the generation of THz waves with phase noise levels of less than –100 dBc Hz^–1, translating to timing noise below 10 as Hz^–1/2 at 10 kHz Fourier frequency, over a carrier frequency range from 300 GHz to 3 THz. This development in phase noise reduction establishes a new benchmark in the spectral purity of tunable THz sources. Such advances are pivotal for applications to move beyond oscillator constraints.

太赫兹 (THz) 频率范围从 0.1 到 10.0 THz，是一个成熟的创新领域，在无线通信和分子光谱等领域具有巨大的发展潜力。我们的工作引入了一种双波长激光器设计，该设计利用光纤腔中的受激布里渊散射来有效地生成两个高度相干的光学斯托克斯波，并本质上减轻了差分相位噪声。为了保证稳定的运行，斯托克斯波被光学注入到各自的泵浦激光器中，这也大大提高了所得的相干性。两个波长之间的频率差通过单行载流子光电二极管转换为太赫兹波。这种创新设计有助于生成相位噪声水平低于 –100 dBc Hz ^–1的太赫兹波，在 10 kHz 傅立叶频率下，定时噪声低于 10 as Hz ^–1/2 ，载波频率范围从 300 GHz 到3太赫兹。相位噪声降低方面的这一进展为可调谐太赫兹源的光谱纯度建立了新的基准。这些进步对于应用超越振荡器限制至关重要。