Content deleted Content added
Citation bot (talk | contribs) Add: s2cid, bibcode, pmid, authors 1-1. Removed parameters. Some additions/deletions were parameter name changes. | Use this bot. Report bugs. | Suggested by Abductive | #UCB_toolbar |
→Overview: rephrasing awkward wording |
||
Line 6:
==Overview==
The OPO consists essentially of an [[Optical cavity|optical resonator]] and a [[Nonlinear optics|nonlinear optical]] crystal. The optical resonator serves to resonate at least one of signal and idler waves. In the nonlinear optical crystal, the pump, signal and idler waves overlap. The interaction between these three waves leads to amplitude gain for signal and idler waves (parametric amplification) and a corresponding deamplification of the pump wave. The gain allows the resonating wave(s) (signal or idler or both) to oscillate in the resonator, compensating the loss that the resonating wave(s) experience(s) at each round-trip. This loss includes the loss due to outcoupling by one of the resonator mirrors, which provides the desired output wave. Since the (relative) loss is independent of the pump power, but the gain is dependent on pump power, at low pump power there is insufficient gain to support oscillation.
The photon conversion efficiency, the number of output photons per unit time in the output signal or idler wave relative to number of pump photons incident per unit time into the OPO can be high, in the range of tens of percent. Typical threshold pump power is between tens of milliwatts to several watts, depending on losses of the resonator, the frequencies of the interacting light, the intensity in the nonlinear material, and its nonlinearity.
There exist both [[continuous-wave]] and [[Pulsed power|pulsed]] OPOs. The latter are easier to build, since the high intensity lasts only for a tiny fraction of a second, which damages the nonlinear optical material and the mirrors less than a continuous high intensity.
| |||