At these a specific wavelength, the light possesses exclusive Qualities which might be priceless to specific Sophisticated applications. Let’s delve further into the significance of this individual light-weight creation.
The 2 frequencies' stage velocities are equivalent whenever they have the very same refractive index. The refractive indices for both of these frequencies are commonly not equivalent, because all media except vacuum are dispersive. Consequently a material's refractive index is dependent upon The sunshine's frequency.
The Rayleigh assortment quantifies the space, measured from your beam waistline, around which the beam diameter is roughly continual. The shorter the Rayleigh array, the more substantial the rate of divergence.
Nevertheless, to completely make use of the potential of BBO crystals, it truly is important to understand their Qualities and how to manage and retail store them appropriately. These crystals require watchful managing to forestall harm to their surfaces and may be saved in a very dry, neat area to keep up their optical general performance.
We use Numerical Aperture (NA) to explain the extent of this angular information. Ideally, the elemental laser light-weight could be collimated all through the crystal, due to the fact collimated light resembles a group of rays aligned to the exact same path by having an NA of zero.
In the situation of Kind-I stage matching and β-BBO crystals, the fundamental light-weight propagates as a rare wave in the crystal, when the second harmonic gentle propagates as an ordinary wave.
Humidity might cause drinking water absorption within the crystal surface, which might degrade its optical performance. The quality of the incident light, such as its wavelength, intensity, and polarization, also can have an impact on the functionality of BBO crystals in many purposes.
The angular content of the focused beam might be visualized by tracing rays from the lens to the focal place. Just about every ray drawn from your lens to your tightly concentrated location (Figure 23) helps make a unique angle (ψ) Along with the chief ray, plus the choice of angles improves with the NA. Given that the range of angles increases past the reference NA filter (or angular area apodization filter width), the phase-matching from the rays outside of the filter width diminishes consequently lessening the SHG conversion performance of All those rays.
When pulse lengths are among one ns and 1 µs, laser-induced harm can take place both as a consequence of absorption or simply a dielectric breakdown (therefore, a user will have to Look at both of those CW and pulsed LIDT). Absorption is possibly due to an intrinsic property of the optic or due to area irregularities; So LIDT values are only legitimate for optics Assembly or exceeding the floor good quality specifications specified by a company.
The SHG light is polarized while in the XZ plane and is particularly orthogonal to both equally the Eo as well as the k-vector. Instead of decompose the polarization of your SHG mild into Ex and Ez factors, the electric area is typically called a rare wave (E'e). The refractive index check here for this extraordinary wave, n'e, alterations as being a purpose of θ. n'e(θ) could be calculated using the equation in Determine 13. The ellipse defining the amazing index of refraction as a operate of θ is really a conic segment with the index ellipsoid.
It can be commonly employed for nonlinear frequency conversion inside the ultraviolet, visible, and around-infrared. The BBO crystal will be the most important nonlinear crystal for near-infrared optical parametric chirped-pulse amplifiers, which presently produce handful of optical cycle pulses with significant common and ultrahigh peak powers.
Tailor made coatings can be placed on the crystal surfaces to reinforce their effectiveness at unique wavelengths or to shield the crystal from environmental things. Having said that, it’s crucial to note that any customization should be done cautiously to avoid degrading the crystal’s optical properties.
Nonetheless, the nonlinear optical Homes of a-BBO crystal is vanished a result of the centric symmetry with its crystal framework. It's not necessarily proposed to employ for NLO procedures.
Moreover, the structural and compositional characteristics of BBO provide it with exceptional thermal balance and resistance towards environmental issues.