Noncritically phase-matched Ti:sapphire-pumped femtosecond optical parametric oscillator based on RbTiOAsO(4)

Spectral broadening in chirped-pulse optical parametric oscillators based on KTiOAsO4

We report a chirped-pulse optical parametric oscillator (CPOPO) based on a KTiOAsO₄ (KTA) crystal. Due to the relatively low ratio between its second-order and third-order nonlinear susceptibility, a single KTA crystal could provide parametric gain and intra-cavity spectral broadening simultaneously in a CPOPO. Numerical simulations show that a signal-bandwidth of 390 nm can be obtained from a KTA-based CPOPO, and the pulses can be de-chirped with a width of ∼20fs outside the OPO cavity. Experimentally, from a fiber-laser-pumped OPO with a 3-mm-long KTA crystal, we obtained a signal wave covering 1332-1667 nm, with a -20dB bandwidth of 45.3 THz, around 12 times as much as the gain-bandwidth of the KTA crystal.

Efficient femtosecond optical parametric oscillator with dual-wavelength operation

We demonstrated on a synchronously pumped femtosecond optical parametric oscillator with dual-signal-wavelength operation. Our results showed that the dual-wavelength oscillation is not determined by the net-zero dispersion but rather by the balance of phase matching and group-velocity mismatching caused by the nonlinear crystal between the two signals. With a MgO-doped periodically poled lithium niobate as the nonlinear crystal, total signal power up to 530 mW was obtained by using a 2.6 W femtosecond Ti:sapphire laser at the central wavelength of 808 nm as the pump source, corresponding to a conversion efficiency of 20.4%. By slightly adjusting the cavity length, the signal wavelength can be broadly tuned from 1001 to 1438 nm and the dual-wavelength tuning range is from 1001 to 1204 nm.

Relaxation oscillation suppression in continuous-wave intracavity optical parametric oscillators

We report a solution to the long standing problem of the occurrence of spontaneous and long-lived bursts of relaxation oscillations which occur when a continuous-wave optical parametric oscillator is operated within the cavity of the parent pump-laser. By placing a second nonlinear crystal within the pump-wave cavity for the purpose of second-harmonic-generation of the pump-wave the additional nonlinear loss thereby arising due to up-conversion effectively suppresses the relaxation oscillations with very little reduction in down-converted power.

Dual-color operation of a femtosecond optical parametric oscillator exhibiting stable relative carrier-envelope phase-slip frequencies

A femtosecond optical parametric oscillator is demonstrated that can operate in a regime where two signal pulses with well-separated center wavelengths are simultaneously resonant. Measurements show that the oscillator output contains a stable modulation at a frequency corresponding to the difference in the carrier-envelope phase-slip frequencies of the co-resonant pulses. The physical origin of this internal beat signal is attributed to second-order mixing effects, and its frequency is shown to be consistent with theory.

Broadly tunable infrared femtosecond optical parametric oscillator based on periodically poled RbTiOAsO(4)

We present results from what we believe is the first reported example of an optical parametric oscillator based on periodically poled RbTiOAsO(4). The oscillator is pumped by a femtosecond self-mode-locked Ti:sapphire laser and, with a single-grating 2-mm-long crystal and one mirror set, a combination of pump and cavity-length tuning provided wavelength coverage from 1060 to 1225nm (signal) and 2.67 to 4.5 microm (idler). Average output powers were as much as 120mW in the signal and 105mW in the idler and interferometric autocorrelations recorded at signal and idler wavelengths of 1.1 and 3.26 microm, respectively, imply pulse durations of 125 and 115fs, respectively.

High-power, high-repetition-rate picosecond optical parametric oscillator tunable in the visible

We describe an intracavity frequency-doubled high repetition-rate picosecond optical parametric oscillator for the visible based solely on the nonlinear crystal LiB(3)O(5) and synchronously pumped by a self-mode-locked Ti:sapphire laser. Under temperature-tuned noncritical type I and type II phase matching, average visible output powers of 320 mW have been generated at an 81-MHz repetition rate. With the available mirror set, continuous tuning from 584 to 771 nm is demonstrated for a range of phase-matching temperatures. Transform-limited pulses with durations of 840-880 fs have been obtained across the visible range for pump pulse durations of 1-1.2 ps.

High-power, high-repetition-rate picosecond optical parametric oscillator for the near- to mid-infrared

A high-repetition-rate, singly resonant optical parametric oscillator based on KTiOAsO(4) and synchronously pumped by a self-mode-locked Ti:sapphire laser is reported. Under the conditions of pump-tuned noncritical type II phase matching, average near-infrared output powers of 403 mW have been generated at a repetition rate of 81 MHz. With the available mirror set, signal tuning over 1.116-1.281 microm and idler tuning over 2.260-3.160 microm are demonstrated for a range of pump wavelengths. Without dispersion compensation, signal (idler) pulses with durations of 1.01-1.03 (1.61-2.91) ps have been obtained for 1.2-ps input pump pulses.

Sub-20-fs tunable pulses in the visible from an 82-MHz optical parametric oscillator

We have produced pulses tunable in the 590-666-nm range, with durations down to 13 fs, using an 82-MHz Ti:sapphire second-harmonic-pumped, high-bandwidth, beta-barium borate optical parametric oscillator in a fused-silica prism group-delay-dispersion-compensated, six-mirror folded ring cavity.