The large volume and weak environmental adaptability of fiber optical frequency combs (OFCs) have become the main obstacles for their applications in various fields. To address these issues, in this study, we present a compact, low-cost f-to-2f interferometer and fiber actuator with a large tuning range and a high control bandwidth for a 200-MHz OFC that is based on a 1.5-m all-polarization-maintaining fiber mode-locked laser. By employing customized fiber-coupled gradient index lenses, our f-to-2f interferometer is encapsulated in a miniature tube with a diameter of only 4 mm and a length of 40 mm, which substantially reduces the optical section size of the frequency comb as compared to conventional devices. The carrier envelope offset beat with a signal-to-noise ratio of 40 dB is detected in a resolution bandwidth of 360 kHz. In addition, a laboratory-made piezoelectric transducer-driven mechanical actuator for repetition rate regulation exhibited a large tuning range of 106 kHz (corresponding to an effective temperature drift of 53) and a high control bandwidth of approximately 1 kHz. This resulted in a robust repetition rate locking with an Allan deviation of 330 Hz at a gate time of 1 s and a residual integrated timing jitter of 418 fs [3 Hz to 1 MHz] when referenced to a hydrogen maser. Along with reducing the size and improving the environmental adaptability of the OFC, our design can also decrease the power consumption of the system significantly. Our findings provide a new direction to the development of OFCs for various applications.

A stable and simple Yb:YAG rod amplifier based on Chirped Pulse Amplification(CPA) in water cooling system has been demonstrated. Output power of 38W at 250 kHz repetition rate with spectrum width of 4nm centered at 1030nm which support Fourier-transform limited pulse duration of 389fs has been generated. Compressed power of 23.9W with pulse duration of 985fs has been obtained with Chirped Volume Brag Grating Compressor (CVBG). The power stability is measured to be 1.414% when the output power is 35W. The system is worthwhile to popularize for its good performance and inexpensive cost.

We demonstrate an all-fiber polarization-maintaining (PM) single-cavity dual-comb fiber laser based on intracavity polarization multiplexing. Two pulse trains share a common cavity section while two partially non-common branches provide independent gain, spectral filtering, and cavity-length control. The repetition rates are approximately 37.281 and 37.270 MHz, giving a repetition-rate difference of about 11 kHz. With radio-frequency (RF)-referenced repetition-rate stabilization, the 1 h standard deviations of $f_{\mathrm{rep}1}$, $f_{\mathrm{rep}2}$, and $\Delta f_{\mathrm{rep}}$, measured with a 1 s gate time, are 290, 178, and 342 $\mathsf{\mu }$Hz, respectively, corresponding to fluctuation-suppression factors of $6.3\times {10}^5$, $1.2\times {10}^6$, and $4.4\times {10}^5$ relative to free-running operation. Stable dual-comb operation is also obtained at discrete, fiber-length-customized working points near 4, 11, and 43 kHz. Autocorrelation measurements give pulse durations of 30.02 and 36.39 ps for the two outputs. A free-space ranging demonstration at $\Delta f_{\mathrm{rep}}=4$ kHz yields a precision of 96.3 $\mathsf{\mu }$m at a 250 $\mathsf{\mu }$s update time, which improves to 2.7 $\mathsf{\mu }$m after averaging 400 points (100 ms). The proposed architecture combines all-fiber PM propagation, branch-level controllability, and RF-referenced repetition-rate stabilization in one single-cavity platform.