Fast, precise, and widely tunable frequency control of an optical parametric oscillator referenced to a frequency comb

Abstract

Optical frequency combs (OFCs) provide a convenient reference for the frequency stabilization of continuous-wave lasers. We demonstrate a frequency control method relying on tracking over a wide range and stabilizing the beat note between the laser and the OFC. The approach combines fast frequency ramps on a millisecond timescale in the entire mode-hop free tuning range of the laser and precise stabilization to single frequencies. We apply it to a commercially available optical parametric oscillator (OPO) and demonstrate tuning over more than 60 GHz with a ramping speed up to 3 GHz/ms. Frequency ramps spanning 15 GHz are performed in less than 10 ms, with the OPO instantly relocked to the OFC after the ramp at any desired frequency. The developed control hardware and software are able to stabilize the OPO to sub-MHz precision and to perform sequences of fast frequency ramps automatically.

Femtosecond fiber lasers for various aspects of quantum technologies

“…Измерения высокого разрешения показали важность квантовой интерференции в мельчайших деталях, а результаты подтверждают сложные вычисления строения атома и потенциал спектроскопии высокой точности для зондирования экзотических ядер [3]. Из второй гармоники эрбиевой частотной гребенки все необходимые длины волны могут охватить диапазон от 780 нм и 795 нм для рубидия и до 1 064 нм и 1 560 для других молекул [9]. Так как различные подгруппы используют гребенку одновременно, то требуется работа в режиме 24 / 7 (24 часа 7 дней в неделю), и часто гребенка и синхронизированные с ней лазеры работают в течение многих месяцев подряд без перерывов.…”

Accurate laser frequency locking to optical frequency combs under low-signal-to-noise-ratio conditions

“…While being nominally less accurate than counting or phase-locking, our method is orders of magnitude more accurate than conventional wavemeters [16,23] and can considerably extend the usable wavelength range of a given optical frequency comb. Also, it is more accurate than other simple schemes used to stabilize lasers to optical frequency combs in conditions of low signal-to-noise ratio [7,22]. Our method is applied to controlling the frequency of a lattice trap in an optical lattice clock [24], which is a representative case where our method is an efficient choice.…”

“…Self-referenced optical frequency combs provide an accurate optical frequency reference over a wide optical bandwidth [6,10,11]. They can be used to measure or stabilize the frequency of continuous-wave (CW) lasers in many applications such as state-of-the-art optical-frequency metrology [4,17], precision spectroscopy [12], laser cooling of atoms [7,19], exciting rovibrational transitions in cold molecules [22], measurement of the frequency of stabilized lasers for length metrology [13], etc. This relies on exploiting the beat note between the CW laser and a tooth of the comb, either by frequency counting or by phase locking [5,12,14].…”