a-BBO Crystal Secrets
a-BBO Crystal Secrets
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The crystal axis is c. The chief ray is parallel into the direction used to evaluate the tuning angle (θ), and that is optimized through period matching. Conversion effectiveness is optimized for rays parallel into the chief ray and even worse for rays at bigger angles (ψ) for the Main ray.
A2: Indeed, prolonged publicity to humidity can degrade the optical overall performance of BBO crystals. Humidity may lead to drinking water absorption on the crystal area, which could influence its optical properties.
The place of your green curve relies on θ. In this instance, the angle θ has actually been tuned to offer a refractive index for 515 nm mild that matches the refractive index for 1030 nm light. This tuning angle is as a result optimized for Variety-I SHG period matching as well as a fundamental-frequency input beam of 1030 nm.
A: Indeed, BBO crystals exhibit extraordinary thermal stability, producing them ideal for apps with various temperatures.
We use Numerical Aperture (NA) to describe the extent of this angular articles. Preferably, the elemental laser gentle will be collimated through the entire crystal, due to the fact collimated mild resembles a gaggle of rays aligned to the identical course with an NA of zero.
Now compare the most electric power density to that that's specified because the LIDT for that optic. If the optic was tested in a wavelength aside from your operating wavelength, the problems threshold needs to be scaled appropriately.
Humidity could cause h2o absorption about the crystal surface area, which might degrade its optical general performance. The standard of the incident mild, which includes its wavelength, intensity, and polarization, may also impact the overall performance of BBO crystals in various programs.
The angular material of the focused beam might be visualized by tracing rays with the lens towards the focal spot. Every single ray drawn within the lens to the tightly concentrated location (Determine 23) makes a different angle (ψ) With all the chief ray, plus the choice of angles raises Together with the NA. Given that the range of angles raises past the reference NA filter (or angular domain apodization filter width), the period-matching with the rays beyond the filter width diminishes therefore lowering the SHG conversion efficiency of those rays.
BBO crystals really should be managed with care to prevent scratching or harming their surfaces. They need to be saved in the dry, neat area and kept faraway from direct daylight. Normal cleansing having a smooth cloth or air blower is usually recommended to maintain their optical effectiveness. When managing BBO crystals, it’s important to use gloves to forestall oils from the pores and skin from contaminating the crystal surface.
The phase velocity is the rate at which the field copyright, i.e. the sine wave, travels in a material. The rate at which a pulse envelope travels in a material is known as the team velocity and defines the velocity from the Vitality packet comprising the optical pulse traveling by the fabric.
The Uncooked elements, commonly a mix of barium carbonate and boric acid, are placed inside a platinum crucible and heated till they melt. The temperature is then steadily reduced, allowing for the BBO crystal to sort above a number of months. The crystal is then extracted, Slash into the specified form, and polished to realize a large-top quality optical surface.
Custom made coatings is often placed on the crystal surfaces to more info improve their overall performance at distinct wavelengths or to safeguard the crystal from environmental things. Nevertheless, it’s imperative that you Observe that any customization needs to be carried out meticulously to stop degrading the crystal’s optical Qualities.
A recommended guideline for concentrating femtosecond laser pulses right into a nonlinear crystal is to keep up a Rayleigh selection that is certainly at the least numerous situations extended when compared to the length with the SHG crystal. This minimizes the chance of detrimental the crystal, as well as minimizes the destructive effects of spatial section mismatch and spatial (Poynting vector) wander-off.
Last of all, spectroscopy, the review of interactions among matter and electromagnetic radiation, greatly Positive aspects in the 266nm technology. In spectroscopic programs, distinctive wavelengths of light interact in another way with resources, supplying a spectrum that could be analyzed to determine the fabric’s properties or composition.