Zijiao Yu

CEO stabilized frequency comb from a 1-μm Kerr-lens mode-locked bulk Yb:CYA laser.

We report the first Kerr-lens mode-locked (KLM) bulk frequency comb in the 1-μm spectral regime. The fundamental KLM Yb:CYA laser is pumped by a low-noise, high-bright 976-nm fiber laser and typically provides 250-mW output power and 57-fs pulse duration. Only 58-mW output pulses were launched into a 1.3-m photonic crystal fiber (PCF) for one octave-spanning supercontinuum generation. Using a simplified collinear f-2f interferometer, the free-running carrier-envelope offset (CEO) frequency was measured to be 42-dB signal-to-noise ratio (SNR) for a 100-kHz resolution and 9.6-kHz full width at half maximum (FWHM) under a 100-Hz resolution. A long-term CEO control at 23 MHz was ultimately realized by feeding the phase error signal to the pump power of the oscillator. The integrated phase noise (IPN) of the locked CEO was measured to be 316 mrad with an integrated range from 1 Hz to 10 MHz. The standard deviation and Allan deviation for more than 4-hour recording are 1.6 mHz and 5.6 × 10(-18) (for 1-s gate time), respectively. This is, to the best of our knowledge, the best stability achieved among the 1-μm solid-state frequency combs.

Diode-pumped high-power Kerr-lens mode-locked Yb:CYA laser

We report on a diode-pumped Kerr-lens mode-locked Yb:CYA laser. Average power as high as 1.5 W was obtained with pulse duration of 68 fs at central wavelength of 1040nm.

Compact frequency comb based on a Kerr-lens mode-locked Yb:CYA laser

We report a compact frequency comb from a fiber-laser pumped KLM Yb:CYA laser. A collinear f-2f interferometer is employed to measure the fceo signal. Low-noise and high stability fceo signal was achieved after electronic feedback.

Frequency doubled femtosecond Ti:sapphire laser with an assisted enhancement cavity*

We report an enhancement cavity for femtosecond Ti:sapphire laser at the repetition rate of 170 MHz. An enhancement factor of 24 is obtained when the injecting pulses have an average power of 1 W and a pulse duration of 80 fs. By placing a BBO crystal at the focus of the cavity, we obtain a 392-mW intracavity doubled-frequency laser, corresponding to a conversion efficiency of 43%. The output power has a long-term stability with a root mean square (RMS) of 0.036%.

Frequency-stabilized Yb:fiber comb with a tapered single-mode fiber*

We demonstrate a stable Yb:fiber frequency comb with supercontinuum generation by using a specially designed tapered single-mode fiber, in which a spectrum spanning from 500 nm to 1500 nm is produced. The carrier-envelope offset signal of the Yb:fiber comb is measured with a signal-to-noise ratio of more than 40 dB and a linewidth narrower than 120 kHz. The repetition rate and carrier-envelope offset signals are simultaneously phase locked to a microwave reference frequency.

Monolithic CEO-stabilization scheme-based frequency comb from an octave-spanning laser*

We demonstrate a carrier-envelope phase-stabilized octave-spanning oscillator based on the monolithic scheme. A wide output spectrum extending from 480 nm to 1050 nm was generated directly from an all-chirped mirror Ti:sapphire laser. After several improvements, the carrier-envelope offset (CEO) beat frequency accessed nearly 60 dB under a resolution of 100 kHz. Using a feedback system with 50-kHz bandwidth, we compressed the residual phase noise to 55 mrad (integrated from 1 Hz to 1 MHz) for the stabilized CEO, corresponding to 23-as timing jitter at the central wavelength of 790 nm. This is, to the best of our knowledge, the smallest timing jitter achieved among the existing octave-spanning laser based frequency combs.

Yb-doped fiber comb based on a tapered single-mode fiber

We present an Yb-doped fiber frequency comb based on a tapered single mode fiber by locking the repetition frequency and the carrier-envelop-offset frequency simultaneously to the microwave frequency reference outside.

Carrier-envelope phase stabilized octave-spanning laser with monolithic scheme

We first demonstrated a carrier-envelope phase (CEP) stabilized octave-spanning oscillator based on the monolithic scheme. Nearly-60 dB CEP offset beat note (RBW=100 kHz) was achieved. The locked CEP residual phase noise is 55mrad, corresponding to timing jitter of only 23 as.

Kerr-lens mode-locked Yb 3+ :CaYAlO 4 laser and octave-spanning supercontinuum generation

We reported a stable Kerr-lens mode-locked Yb3+:CaYAlO4 oscillator. The shortest pulse duration was measured to be 57fs and the maximum mode-locked power was more than 1W. An octave-spanning supercontinuum in a PCF was also generated.