Misalignment-free, Kerr-lens-modelocked Yb:YO 2.2-GHz oscillator, amplified by a semiconductor optical amplifier.

We present a fully bonded, misalignment-free, diode-pumped Yb:ceramic (Yb:YO) oscillator producing 190-fs pulses at a repetition frequency of 2.185 GHz. Self-starting Kerr-lens-modelocked operation was obtained from both outputs of the ring cavity with an average combined output power of 14-30 mW for pump powers from 380-670 mW.

Towards a space-qualified Kerr-lens mode-locked laser.

We report a 1.5-GHz Kerr-lens mode-locked (KLM) Yb: ring laser constructed by directly bonding the cavity components onto an aluminum baseplate. Stable unidirectional operation with an output power ≥10 was obtained for pump-diode currents of 300-500 mA, corresponding to a total electrical power consumption of 1.

The Rydberg constant and proton size from atomic hydrogen.

At the core of the "proton radius puzzle" is a four-standard deviation discrepancy between the proton root-mean-square charge radii () determined from the regular hydrogen (H) and the muonic hydrogen (µp) atoms. Using a cryogenic beam of H atoms, we measured the 2S-4P transition frequency in H, yielding the values of the Rydberg constant = 10973731.568076(96) per meterand = 0.

(87)Rb-stabilized 375-MHz Yb:fiber femtosecond frequency comb.

We report a fully stabilized 1030-nm Yb-fiber frequency comb operating at a pulse repetition frequency of 375 MHz. The comb spacing was referenced to a Rb-stabilized microwave synthesizer and the comb offset was stabilized by generating a super-continuum containing a coherent component at 780.2 nm which was heterodyned with a (87)Rb-stabilized external cavity diode laser to produce a radio-frequency beat used to actuate the carrier-envelope offset frequency of the Yb-fiber laser.

650-nJ pulses from a cavity-dumped Yb:fiber-pumped ultrafast optical parametric oscillator.

Sub-250-fs pulses with energies of up to 650 nJ and peak powers up to 2.07 MW were generated from a cavity-dumped optical parametric oscillator, synchronously-pumped at 15.3 MHz with sub-400-fs pulses from an Yb:fiber laser.

Wavelength stabilization of a synchronously pumped optical parametric oscillator: optimizing proportional-integral control.

We describe a formal approach to the wavelength stabilization of a synchronously pumped ultrafast optical parametric oscillator using proportional-integral feedback control. Closed-loop wavelength stabilization was implemented by using a position-sensitive detector as a sensor and a piezoelectric transducer to modify the cavity length of the oscillator. By characterizing the frequency response of the loop components, we constructed a predictive model of the controller which showed formally that a proportional-only feedback was insufficient to eliminate the steady state error, consistent with experimental observations.