Not known Facts About a-BBO Crystal
Not known Facts About a-BBO Crystal
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The crystal axis is c. The Main ray is parallel to the direction used to evaluate the tuning angle (θ), and that is optimized through section matching. Conversion performance is optimized for rays parallel to your chief ray and worse for rays at more substantial angles (ψ) on the Main ray.
The two frequencies' period velocities are equivalent if they hold the identical refractive index. The refractive indices for these two frequencies are normally not equal, because all media besides vacuum are dispersive. Because of this a cloth's refractive index depends upon the light's frequency.
Howdy, thank you for contacting Thorlabs. The wavelength ranges from the antireflective coatings on these β-BBO crystals align Along with the respective wavelength bands that these crystals are optimized for. Requests for customizations is usually produced by reaching out to us at [email protected]
Beam diameter is usually crucial that you know when evaluating problems thresholds. Even though the LIDT, when expressed in models of J/cm², scales independently of place dimensions; significant beam measurements are more likely to illuminate a bigger amount of defects which can result in higher variances from the LIDT [four].
From the ray-product point of view, the propagation course defines the orientation on the central (Main) ray in Figure 23. The SHG process is afflicted through the selection of angles more than which incident gentle propagates, due to the fact light that's not parallel for the chief ray has decreased phase-matching relative towards the chief ray.
The efficiency from the SHG course of action decreases significantly as the fundamental beam diverges from its emphasis, Because the pulse Electrical power is distributed throughout a larger beam cross area.
Determine 18: The everyday and remarkable refractive indices of β-BBO range with frequency and wavelength as a result of a fabric property identified as dispersion. Dispersion exists in all media apart from vacuum.
The angular content of a centered beam might be visualized by tracing rays from the lens on the focal location. Each and every ray drawn with the lens to a tightly focused spot (Determine 23) will make a different angle (ψ) With all the chief ray, plus the number of angles boosts While using the NA. As the selection of angles raises past the reference NA filter (or angular domain apodization filter width), the phase-matching from the rays beyond the filter width diminishes therefore decreasing the SHG conversion efficiency of Individuals rays.
BBO crystals should read more be dealt with with treatment in order to avoid scratching or damaging their surfaces. They must be stored within a dry, cool position and stored clear of direct daylight. Normal cleansing using a comfortable cloth or air blower is usually recommended to keep up their optical effectiveness. When dealing with BBO crystals, it’s important to use gloves to forestall oils from the pores and skin from contaminating the crystal surface.
Therefore, the next harmonic pulse spectrum, proven on the best, incorporates a spectral width approximately the same as The perfect case. Preferably, every frequency in the basic pulse spectrum will be simultaneously section matched.
As might be mentioned below, You will find a focusing numerical aperture (NA) limitation into the SHG stage-matching course of action particularly analogous into the spectral stage matching limitation discussed during the preceding section (
This fantastic-tuning capacity ensures that BBO crystals can cater to both generic and hugely specialised requirements with equivalent finesse.
The physical, chemical, optical, and thermal Houses from the α -BBO are just like These with the BBO crystals, but the α -BBO isn't going to show the nonlinear optical Homes due to central symmetry of its crystal structure.
On top of that, the structural and compositional characteristics of BBO deliver it with extraordinary thermal steadiness and resistance from environmental troubles.