Following the mixture has actually been completely melted, it truly is then allowed to amazing slowly and gradually. This gradual cooling course of action is critical, as it permits BBO crystals to kind slowly in the liquid mixture. The rate of cooling is meticulously regulated to market The expansion of huge, significant-quality crystals.
Next, the power/Power is possibly enhanced or decreased plus the optic is uncovered at 10 new places. This process is recurring till destruction is noticed. The damage threshold is then assigned being the highest ability/Power that the optic can face up to with out producing problems. A histogram for instance that below represents the tests of one BB1-E02 mirror.
From a ray-model point of view, the propagation direction defines the orientation in the central (chief) ray in Determine 23. The SHG method is afflicted because of the choice of angles over which incident light propagates, since gentle that is not parallel for the Main ray has decreased section-matching relative on the chief ray.
In an effort to use the required CW hurt threshold of an optic, it is necessary to be aware of the following:
Typically, the crystal content ought to have a higher optical transparency for all wavelengths involved �?one example is, for pump, sign and idler in an optical parametric amplifier.
Significant harm threshold: BBO crystals have large destruction restrictions that could stand up to their superior best and regular power without having degradation or harm.
You should Observe that We've a buffer built between the specified hurt thresholds on the internet and the tests which Now we have finished, which accommodates variation among batches. On ask for, we can offer person exam facts and a testing certification.
A next worry would be that the group velocity mismatch between the second harmonic and elementary-frequency pulses will bring about one pulse lagging the other as the two propagate. This is termed temporal wander-off and may take place even less than optimal section-matched problems.
Large-precision laser microfabrication is a BBO Crystal way the place elements are processed and modified over a microscopic scale. This method demands a laser source that can generate really targeted and specific beams of sunshine. The 266nm wavelength is very suitable for this on account of its small wavelength, which makes sure that the laser beam might be centered to an exceptionally compact spot dimension.
For CPM, we Slice our parts at an angle equivalent to no or 90 ranges stressing among the list of main axes. For NCPM, we decreased our merchandise at an angle based on Snell’s regulation:
The four decreased figures illustrate that the group velocity hold off (temporal wander-off) improves because the pulses propagate through the fabric. The temporal stroll-off is illustrated for distances Z0 via Z3, which can be indicated on the diagram at best.
The spectrally narrowed SHG pulse spectrum is claimed being apodized, due to the fact an influence of the basic pulse exceeding the most enter bandwidth Restrict would be the removal of the very best and lowest frequencies within the SHG pulse spectrum.
The temporal walk-off is commonly viewed as extreme in the event the temporal lag exceeds the duration of the basic pulse. Severe walk-off may result in temporal lag that irreparably raises the period of the output 2nd harmonic pulse.
The size from the SHG crystal noticeably impacts the spectral width of your reference pulse, or alternatively the bandwidth on the SHG filter.