Atomic spectroscopy serves as the basis for quantum precision measurements, where frequency-stabilized lasers are crucial for obtaining accurate atomic spectra.This work introduces a compact laser frequency stabilization system that employs a multifunctional metasurface to adjust the polarization, amplitude, and propagation direction of incident light.By combining with a Rb atomic vapor cell, the system achieves a tunable sub-Doppler spectrum for laser frequency stabilization.The experimental result demonstrates that a laser frequency stability of 3 × 10 -11 is attained from 1 to 200 s at 780 nm with the input power at 20 μW.The devices hold significant potential for compactness, integration, and mass production, making them highly suitable for quantum measurement applications.
Atomic spectroscopy serves as the basis for quantum precision measurements, where frequency-stabilized lasers are crucial for obtaining accurate atomic spectra.This work introduces a compact laser frequency stabilization system that employs a multifunctional metasurface to adjust the polarization, amplitude, and propagation direction of incident light.By combining with a Rb atomic vapor cell, the system achieves a tunable sub-Doppler spectrum for laser frequency stabilization.The experimental result demonstrates that a laser frequency stability of 3 × 10 -11 is attained from 1 to 200 s at 780 nm with the input power at 20 μW.The devices hold significant potential for compactness, integration, and mass production, making them highly suitable for quantum measurement applications.
We report on the atomic spectroscopy and laser frequency stabilization using a new type of a miniaturized glass vapor cell with a scalable thickness varying from 500 nm up to 8 μm. The cell is fabricated by lithography and etching techniques in a Pyrex glass substrate, followed by anodic bonding. It is filled with rubidium vapor using a distillation procedure. This simple and cost-effective fabrication method provides an attractive and compact solution for atomic cells, with applications in quantum metrology, sensing, communication, and light-vapor manipulations at the subwavelength scale. Using the fabricated cell, we have performed fluorescence and transmission spectroscopy of the Rubidium D2 line and observed sub-Doppler broadened lines. As an example, for a potential application, we have used the fabricated cell to demonstrate the stabilization of a 780 nm diode laser to the level about 10−10 in fractional frequency.
Abstract Compact and robust structures to precisely control and acquire atomic spectra are increasingly important for the pursuit of widespread applications. Sub‐Doppler responses of thermal atoms are critical in constructing high‐precision devices and systems. In this study, a nanograting metasurface specifically is designed for atomic rubidium vapor and integrated it into a miniature vapor cell. Using the metasurface with built‐in multifunctional controls for light, pump‐probe atomic spectroscopy is established and sub‐Doppler responses are experimentally observed at low incident power. Moreover, the sub‐Doppler lineshape can be tailored by varying the incident polarization state. The spectrum transformation from absorption to transparency is observed. Using one of the sharp responses, laser stabilization with a stability of at 2 s can be achieved. This work reveals the effective control of atomic spectra with optical metasurface chips, which may have great potential for future developments in fundamental optics and novel optical applications.
Abstract Locking laser frequencies to Doppler-free spectra produced by the interaction of light with alkali atoms in a vapor cell is a promising approach for realizing compact atomic optical frequency reference. In this work, we employ counter-propagating monochromatic laser beams with a polarization angle of 45° to interact with 87 Rb atoms in a 3 mm cubic vapor cell, inducing coherent resonance. By detecting the laser polarization rotation, we obtain a Doppler free spectral line, which is used as a reference for laser frequency locking, thus realizing an optical reference. We build two nominally identical systems and measure their beatnote, yielding a fractional frequency stability of 5.3×10 -13 at 1 s. This study demonstrates that the proposed scheme is a competitive approach for realizing high performance compact atomic optical reference.
Precise laser stabilization is a fundamental aspect of modern metrology, directly influencing the accuracy of fundamental measurements in fields such as high-precision metrology, atomic sensor applications, and quantum technologies. Saturation absorption spectroscopy (SAS) is one of the most effective techniques for achieving high spectral stability, as it enables laser frequencies to be locked to atomic resonances. This technique exploits the nonlinear interaction between a weaker probe beam and a stronger pump beam within a rubidium (Rb) atomic vapor cell. By eliminating Doppler broadening, SAS allows well-defined hyperfine transitions to be resolved, providing a reliable optical frequency reference. This study aims to optimize laser frequency stabilization using the SAS technique by investigating the effects of laser light polarization, atomic vapor cell temperature, and pump-probe power adjustments. Polarization-dependent selection rules influence transition probabilities, thereby affecting spectral contrast and frequency stability. Additionally, atomic density variations, which depend on the vapor cell temperature, influence signal strength and linewidth, necessitating precise temperature control for optimal performance. Furthermore, the pump power must be sufficient to induce saturation without excessive power broadening, while the probe power must remain low enough to prevent spectral line distortion. By optimizing polarization, temperature, and power parameters, the stabilization of the Rb atomic laser can be enhanced, leading to improved reproducibility and consistency in high-precision measurements. SAS-based laser stabilization is particularly crucial for atomic sensor applications and quantum technologies, where highly stable, narrow-linewidth lasers are essential for precision measurements. Applications such as atomic magnetometers, gyroscopes, and inertial navigation systems depend on precisely stabilized lasers for optimal performance. By enhancing the reliability of laser frequency stabilization, this work contributes to the advancement of next-generation atomic sensors with improved sensitivity and stability.
The utilization of atomic or molecular spectroscopy for frequency locking of single-frequency laser to improve laser frequency stability plays an important role in the experimental investigation of optically pumped atomic magnetometers, atomic clocks, laser cooling and trapping of atoms, etc. We have experimentally demonstrated a technique for frequency stabilization of a single-frequency laser employing the bright state spectroscopy (BSS) with a rubidium atomic vapor cell. By utilizing the counter-propagating dual-frequency 795 nm laser beams with mutually orthogonal linear polarization and a frequency difference of 6.834 GHz, which is equal to the hyperfine splitting of rubidium-87 ground state 5S1/2, an absorption-enhanced signal with narrow linewidth at the center of Doppler-broadened transmission spectroscopy is observed when continuous scanning the laser frequency over rubidium-87 D1 transition. This is the so-called BSS. Amplitude of the absorption-enhanced signal in the BSS is much larger compared with the conventional saturation absorption spectroscopy (SAS). The relationship between linewidth and amplitude of the BSS signal and laser beam intensity has been investigated. This high-contrast absorption-enhanced BSS signal has been employed for the laser frequency stabilization. The experimental results show that the frequency stability is 4.4×10−11 with an integration time of 40 s, near one order of magnitude better than that for using the SAS.
We present the development and complete spectral characterization of our compact and frequency-stabilized laser heads, to be used for rubidium atomic clocks and basic spectroscopy. The light source is a Distributed Feed-Back (DFB) laser diode emitting at 780 nm or 795 nm. The laser frequency is stabilized on a sub-Doppler absorption peak of the 87Rb atom, obtained from an evacuated rubidium cell. These laser heads, including the electronics for the light signals detection, have an overall volume of 0.63 liters. We also present a variant of the laser head into which is integrated an Acousto-Optical Modulator (AOM) that precisely detunes the laser frequency in order to minimize the AC Stark shift in Rb atomic clocks.