The 2-Minute Rule for a-BBO Crystal
The 2-Minute Rule for a-BBO Crystal
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The elemental discipline now driving the kind-I SHG approach could be the Eoγ ingredient with the incident subject. At γ = 90°, there could well be zero SHG output, Because the travel subject Eoγ = 0.
Regretably, it can be quite challenging to compare the LIDT specification of an optic in your laser. You will discover several regimes through which a pulsed laser can harm an optic which is predicated about the laser's pulse length. The highlighted columns during the table underneath outline the appropriate pulse lengths for our specified LIDT values.
The energy in both equally waves propagates in directions based on their Poynting vectors. Snell's legislation doesn't explain the course of Strength movement, but it may be used to calculate the course from the k-vector inside the crystal.
Instead of the reference pulse ability spectrum comprising an apodization filter, while in the spatial area the filter could well be in NA. The angular domain apodization filter even so, is simply in one-dimension defined through the airplane k and .
Several variables can have an affect on the performance of BBO crystals. These contain temperature, humidity, and the caliber of the incident light. Appropriate handling and storage will help sustain the crystal’s performance. Temperature can influence the phase-matching disorders of BBO crystals, which subsequently affects their efficiency in frequency conversion purposes.
As the second harmonic gentle propagates, its Power flows in a unique way than that of the basic light.
The spatial walk-off angle relies on the dimensions with the beam and also the crystal duration. When the angle can be considerable, it is usually small, ordinarily on the buy of ten mrad, and can be neglected.
As illustrated in the next table, the shorter the crystal, the broader the reference pulse spectrum. The desk beneath assumes a fundamental Heart wavelength from the close to-IR.
But BBO crystals stand resilient, guaranteeing that techniques proceed to function devoid of hiccups, minimizing downtimes and making certain Price-success Over time.
The SHG mild is polarized in the XZ airplane and is orthogonal to both equally the Eo and also the k-vector. In lieu of decompose the polarization on the SHG light-weight into Ex and Ez parts, the electric subject is typically described as an extraordinary wave (E'e). The refractive index for this remarkable wave, n'e, changes like a operate of θ. n'e(θ) may be calculated utilizing the equation in Figure 13. The ellipse defining the amazing index of refraction for a perform of θ is a conic segment from the index ellipsoid.
This calculation assumes a uniform beam depth profile. You must now adjust this Power density to account for hotspots or other nonuniform intensity profiles and about determine a optimum energy density. For reference a Gaussian beam commonly contains a optimum energy density which is two times that of your 1/e2 beam.
Tailor made coatings may be applied to the crystal surfaces to boost their functionality at precise wavelengths or to protect the crystal from environmental components. Even so, it’s essential to Be aware that any customization must be carried out very carefully to avoid degrading the crystal’s optical properties.
A encouraged guideline for concentrating femtosecond laser pulses into a nonlinear crystal is to maintain a Rayleigh vary that is definitely no less than many instances lengthier than the size in more info the SHG crystal. This minimizes the chance of detrimental the crystal, along with reduces the detrimental results of spatial section mismatch and spatial (Poynting vector) stroll-off.
Additionally, the structural and compositional attributes of BBO supply it with impressive thermal balance and resistance towards environmental worries.