a-BBO Crystal Fundamentals Explained
a-BBO Crystal Fundamentals Explained
Blog Article
Standard cleansing and suitable storage may also help prolong the lifespan of BBO crystals. It’s also imperative that you avoid exposing the crystals to disorders outside the house their specified operating variety, as this might cause long term harm.
The 266nm wavelength provides specific interactions that other wavelengths can’t, making it indispensable for detecting and researching sure compounds.
The Rayleigh selection quantifies the gap, calculated from the beam waist, in excess of which the beam diameter is close to regular. The shorter the Rayleigh variety, the more substantial the rate of divergence.
However, it’s imperative that you Observe that although BBO crystals can cope with significant electricity, they need to continue to be employed inside of their specified electric power vary to avoid likely injury and make certain optimal general performance.
Any contamination can degrade the optical efficiency of your crystal and possibly lead to damage below large laser energy. When storing BBO crystals, they should be placed in a very protecting circumstance to stop Bodily damage and dirt accumulation.
The four lessen figures illustrate which the group velocity delay (temporal walk-off) improves since the pulses propagate via the fabric. The temporal walk-off is illustrated for distances Z0 by way of Z3, which happen to be indicated around the diagram at best.
Bodily, when the fundamental spectrum is well within the reference pulse spectrum, the SHG pulse depth profile is definitely the sq. of the basic depth profile, effectively truncating the period. website This case is illustrated in Determine twenty.
The angular content material of the centered beam could be visualized by tracing rays with the lens to the focal spot. Just about every ray drawn in the lens to the tightly centered location (Determine 23) will make another angle (ψ) While using the chief ray, as well as the array of angles raises Along with the NA. Since the number of angles improves past the reference NA filter (or angular domain apodization filter width), the period-matching of the rays beyond the filter width diminishes therefore reducing the SHG conversion performance of those rays.
Assuming a crystal of the provided thickness, it is achievable to determine a reference pulse which has a spectral vary that is the utmost that can be adequately period matched. This spectral bandwidth limitation will also be considered regarding an SHG spectral filter whose passband relies on both the precise crystal and the heartbeat's Centre frequency. Frequencies outside of this filter’s passband will be turned down from going through the SHG approach.
As a result, the next harmonic pulse spectrum, revealed on the proper, features a spectral width somewhere around similar to The best case. Preferably, each individual frequency in the basic pulse spectrum can be at the same time period matched.
As are going to be discussed below, You will find there's focusing numerical aperture (NA) limitation to the SHG phase-matching course of action exactly analogous into the spectral stage matching limitation mentioned in the former part (
This fine-tuning capacity ensures that BBO crystals can cater to both generic and remarkably specialised desires with equivalent finesse.
Various various period-matching approaches can be utilized to equalize the refractive indices of the elemental and next harmonic light. A single approach, which utilizes linearly polarized light as well as the distinction between the regular and incredible refractive indices, is Style-I critical phase matching. This can be a typical strategy for damaging uniaxial crystals wherein no > ne.
This has not simply expanded the capabilities of existing systems but has also paved the way in which For brand spanking new improvements.