Optical frequency standard using acetylene-filled hollow-core photonic crystal fibers

Abstract

Abstract:Gas-filled hollow-core photonic crystal fibers are used to stabilize a fiber laser to the 13 C 2 H 2 P(16) (ν 1 + ν 3 ) transition at 1542 nm using saturated absorption. Four hollow-core fibers with different crystal structure are compared in terms of long term lock-point repeatability and fractional frequency instability. The locked fiber laser shows a fractional frequency instability below 4 × 10 −12 for averaging time up to 10 4 s. The lock-point repeatability over more than 1 year is 1.3 × 10 −11 , corresponding to a standard deviation of 2.5 kHz. A complete experimental investigation of the light-matter interaction between the spatial modes excited in the fibers and the frequency of the locked laser is presented. A simple theoretical model that explains the interaction is also developed.

Compact, CO_2-stabilized tuneable laser at 205 microns

“…Here, it can be seen that the current fiber has a higher order mode cut-off at around 2070 nm, below which the fiber only supports a single spatial core mode. The relatively flat response at a differential group index of approximately 0.1 is an artefact of the measurement equipment similar to the one observed in [1]. The complete optical part of the setup fits in a compact box with dimensions (25 × 25 × 5) cm 3 .…”

“…Since the effective error signal slope decreases away from resonance, large offsets typically display a higher instability than small offsets. Figure 7 shows the Allan deviation of two representative measurements of +50 MHz and +200 MHz offset frequencies marked by (1) and (2) in Fig. 6.…”

“…Current state-of-the-art laser frequency stabilisation using gas-filled hollow-core fibres have demonstrated a relative long-term instability of about 4 × 10 −12 and relative short-term instability of about 2 × 10 −12 for one second averaging time [1][2][3]. These results were obtained with acetylene and iodine using saturated absorption spectroscopy, which gives linewidths of typically 20 MHz.…”

Semiconductor frequency standard based on p(16) spectral line of acetylene isotope with temperature stabilization by phase modulation

“…Основные источники лазерного излучения на 1,5 мкм -это лазерные диоды (ЛД) (с распределен-ной обратной связью (РОС) [4,5,8,9] и с внешним резонатором [5][6][7], а также с дополнительным резона-тором на шепчущих модах [11]), волоконные эрбиевые лазеры [10] и твердотельный Er-Yb лазер [3]. В каждом из случаев были показаны высокие для рабочего стандарта частоты результаты.…”

Frequency-stabilized laser system at 1572 nm for space-borne CO2 detection LIDAR

“…However, the absorption of the 1572.0179 nm line is very weak, so in order to get enough absorption, the length of the reference cell should be very long (typically >10 m). During the last decade, gas-filled hollow-core fibers have been widely investigated and could be used to build the light, compact reference cells [15][16][17] . But, the surface and high-order modes exhibited in these fibers lead to higher power loss and wavelength-dependent coupling to core modes, causing strong multipath interference (MPI), which limited the frequency stability to the MHz level, which is insufficient for the CO 2 LIDAR application.…”