Compact, high-pulse-energy, picosecond optical parametric oscillator

Abstract

We report a high-energy optical parametric oscillator (OPO) synchronously pumped by a 7.19 MHz, Yb:fiber-amplified, picosecond, gain-switched laser diode. The 42-m-long ring cavity maintains a compact design through the use of an intracavity optical fiber. The periodically poled MgO-doped LiNbO(3) OPO provides output pulse energies as high as 0.49 μJ at 1.5 μm (signal) and 0.19 μJ at 3.6 μm (idler). Tunability from 1.5 to 1.7 μm and from 2.9 to 3.6 μm is demonstrated, and typical M(2) values of 1.5 × 1.3 and 2.8 × 1.9 are measured for the signal and idler, respectively, at high power.

High-energy, near- and mid-IR picosecond pulses generated by a fiber-MOPA-pumped optical parametric generator and amplifier

“…As an example, an optical parametric amplifier (OPA) pumped by a fiber chirped-pulse amplification source has generated femtosecond pulses with energies as high as 1.2 μJ in the near-IR [11]. Using a 7.19 MHz, Yb-fiber MOPA system, employing similar direct amplification to the system described here, but with a more complex OPO configuration, pulse energies as high as 0.49 μJ at 1.5 μm and 0.19 μJ at 3.6 μm have been demonstrated with ~100 ps pulses [12].…”

High-power PPMgLN-based optical parametric oscillator pumped by a linearly polarized, semi-fiber-coupled acousto-optic Q-switched fiber master oscillator power amplifier

“…According to these requirements, fiber lasers are supposed to be the best candidates among all the OPO pump sources due to their compactness, robustness, excellent beam quality, and simple thermal management schemes [3]. Therefore, fiber-laser-pumped OPOs have been extensively investigated from continuous wave (CW) to ultrashort pulsed operation schemes [4][5][6][7][8][9][10][11][12][13]. Among all these pump sources, fiber lasers with tens to hundreds of nanoseconds are particularly useful in outdoor applications for both environmental monitoring and missile countermeasures because simple linear cavities are applicable to such pump sources converting the pump power to idler output efficiently during each pulse with peak power higher than the CW OPOs and dimensions smaller than the synchronously pumped OPOs.…”

Green-pumped, picosecond MgO:PPLN optical parametric oscillator

“…Nevertheless, LN is still an interesting crystal compared to bulk crystals such as LBO for use in green-pumped, ultrashort-pulse OPOs due to its advantageous properties such as the high nonlinear coefficient d eff = 17pm/V, the possibility of engineered phase-matching by periodic poling, the well-known physical and optical properties, the wide availability and the low price. A viable option for an efficient, pulsed, greenpumped OPO based on MgO:PPLN could be a low pump repetition rate of a few megahertz and a long but still compact fiber-feedback OPO resonator [25,33], where the average power is low but the peak intensity is relatively high.…”

“…A mechanical chopper with a 1:9 duty cycle and a frequency of 150Hz was placed in the pump beam to transmit 10% and block 90% of the total power ('transmit' period 0.67ms, 'block' period 6ms). Note that a reduction of the pump source repetition rate to tens of megahertz would have the same effect, but this would be less practical, since a much longer OPO cavity, for example with a fiber for signal feedback [25,33], and hence a complete re-alignment of the OPO would be required. During the 'transmit' cycle, the peak intensity of the focused picosecond pulses remained unaltered and hence the threshold unaffected.…”