5 Simple Techniques For BBO Crystal
5 Simple Techniques For BBO Crystal
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This short article dives deep into the advantages and exceptional Homes of BBO crystal and its paramount worth in efficient frequency doubling and harmonics era at 266nm.
The selection of your most fitted crystal material for any supplied software is usually far from trivial; it need to entail the consideration of many aspects. One example is, a higher nonlinearity for frequency conversion of ultrashort pulses will not help When the conversation size is strongly constrained by a substantial group velocity mismatch as well as small injury threshold limitations the applicable optical intensities.
Once the Rayleigh assortment is under the crystal thickness, the distance more than which the beam is optimally powerful is lower than the crystal thickness.
) is The main element for BBO to get high conversion performance. Limited aim of laser beam just isn't suggested.
As opposed to the reference pulse ability spectrum comprising an apodization filter, inside the spatial domain the filter can be in NA. The angular area apodization filter however, is only in one-dimension described because of the airplane k and .
A common method for getting ultrathin crystals should be to very first optically Make contact with a thicker nonlinear crystal with some substrate (e.g. of fused silica) and then to shine the crystal all the way down to the demanded thickness of e.
Figure eighteen: The normal and extraordinary refractive indices of β-BBO change with frequency and wavelength due to a cloth property referred to as dispersion. Dispersion exists in all media apart from vacuum.
A 2nd issue would be that the group velocity mismatch involving the 2nd harmonic and essential-frequency pulses will bring about a person pulse lagging the opposite as The 2 propagate. This is named temporal walk-off and can happen even below optimum phase-matched disorders.
Large-precision laser microfabrication is a method in which resources are processed and modified on a microscopic scale. This method needs a laser source that could create particularly focused and precise beams of light. The 266nm wavelength is especially well suited for this as a result of its brief wavelength, which makes certain that the laser beam is often centered to an extremely small spot sizing.
The Power density of the beam should be calculated with regards to J/cm2. The graph to the appropriate demonstrates why expressing the LIDT being an Power density presents the most beneficial metric for brief pulse resources. Within this regime, the LIDT presented being an Vitality density may be applied to any beam diameter; just one does not need to compute an modified LIDT to regulate for adjustments in place size.
Alternatively, a small enclosure (with openings for gentle) can be crafted within the crystal by using a constant flow of dry nitrogen of air in the enclosure. The dry nitrogen/air pressure needs only to generally be somewhat above the ambiance to keep the small volume throughout the crystal dry and clean.
Also, it get more info can be really fascinating to utilize a crystal material that may be critically stage-matched at place temperature since noncritical period matching frequently consists of the operation in the crystal inside of a temperature-stabilized crystal oven. Nonetheless, the feasibility of important section matching might be given only for sufficiently superior peak powers.
The wavelength of the light employed as well as angle at which it enters the crystal may affect the crystal’s functionality. Proper alignment and dealing with of your crystal are essential to obtaining optimal functionality.
Considering that the refractive index does not differ linearly with frequency in dispersive crystals like β-BBO, it is actually not possible to optimally section match every single frequency in the input pulse's spectral vary With all the corresponding next harmonic frequency within the produced pulse.