The Definitive Guide to a-BBO Crystal
The Definitive Guide to a-BBO Crystal
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The crystal axis is c. The Main ray is parallel towards the way utilized to measure the tuning angle (θ), which is optimized during section matching. Conversion efficiency is optimized for rays parallel for the Main ray and even worse for rays at larger angles (ψ) to your Main ray.
Beta Barium Borate (BBO) crystals have been a subject of fascination in the sector of optics and photonics because of their unique Attributes. In this post, we purpose to answer ten popular questions about BBO crystals, giving an extensive comprehension of this fascinating product.
A next worry would be that the team velocity mismatch among the next harmonic and basic-frequency pulses will lead to a person pulse lagging one other as The 2 propagate. This is known as temporal walk-off and will happen even beneath best period-matched conditions.
This effectiveness is significant, particularly when a person considers the generation with the 266nm wavelength, the place even insignificant inefficiencies may lead to substantial Electrical power losses.
Various elements can influence the functionality of BBO crystals. These contain temperature, humidity, and the standard of the incident mild. Appropriate handling and storage can assist preserve the crystal’s general performance. Temperature can affect the section-matching situations of BBO crystals, which consequently affects their efficiency in frequency conversion purposes.
). This spatial focusing constraint about the SHG course of action will generally lead to the crystal length constantly currently being under the Rayleigh variety of the input targeted pulse.
In some instances, the mismatch may be little. For instance, each time a β-BBO crystal is used to frequency double 1550 nm light and supply 775 nm gentle, the group velocity mismatch is only some femtoseconds for each millimeter.
As illustrated in the next table, the shorter the crystal, the broader the reference pulse spectrum. The table below assumes a essential center wavelength in the near-IR.
Since the refractive index does not change linearly with frequency in dispersive crystals like β-BBO, it truly is impossible to optimally stage match each and every frequency in the enter pulse's spectral assortment With all the corresponding second harmonic frequency during the produced pulse.
Consequently, the second harmonic pulse spectrum, demonstrated on the proper, has a spectral width around similar to the ideal circumstance. Preferably, each individual frequency in the elemental pulse spectrum can be simultaneously stage matched.
Thorlabs offers a large choice of optics optimized to be used with femtosecond and picosecond laser pulses. Remember to see below for more information.
For the reason that dynamics of this process are extremely topic to experimental parameters, it is difficult to arbitrarily forecast the exact results on the second harmonic pulse. These consequences can involve again conversion, during which next harmonic gentle is converted back to elementary mild, and spectral narrowing of your SHG pulse.
Nevertheless, the nonlinear optical Houses of a-BBO crystal is vanished due to centric symmetry with its crystal construction. It's not necessarily proposed to utilize for NLO procedures.
Additionally, the structural and compositional more info attributes of BBO supply it with remarkable thermal steadiness and resistance versus environmental worries.