Substantial-precision laser microfabrication is a technique the place resources are processed and modified over a microscopic scale. This process needs a laser resource which can develop incredibly concentrated and precise beams of light. The 266nm wavelength is very suitable for this as a consequence of its small wavelength, which makes certain that the laser beam could be centered to an extremely tiny spot dimension.
The group velocities of the basic and 2nd harmonic pulses also are diverse, even if section-matched, as well as magnitude on the group velocity mismatch is determined by the crystal Houses along with the optical frequencies inside the pulses.
There's two velocities that define the propagation of sunshine in optical media: the section and team velocities. The period velocity would be the speed on the copyright, the oscillation of the electric area, and the velocity that may be matched concerning the elemental and second harmonic frequencies for stage matching. The section velocity relative on the velocity of light in the vacuum is outlined by the index of refraction.
However, to totally use the potential of BBO crystals, it truly is essential to be familiar with their properties and how to deal with and retail store them appropriately. These crystals call for very careful managing to stop damage to their surfaces and should be saved within a dry, cool spot to keep up their optical performance.
BBO crystals is often cleaned utilizing a tender fabric or air blower. For stubborn stains, a mild detergent or isopropyl Alcoholic beverages can be utilized. It’s crucial to steer clear of utilizing abrasive materials which could scratch the crystal’s surface. When cleaning BBO crystals, it’s crucial to use a delicate, round motion in order to avoid scratching the surface area.
Make sure you note that We now have a buffer built between the specified damage thresholds on the internet and the assessments which We've finished, which accommodates variation in between batches. Upon ask for, we can provide personal test data as well as a testing certification.
Determine eighteen: The ordinary and remarkable refractive indices of β-BBO range with frequency and wavelength on account of a cloth house termed dispersion. Dispersion exists in all media besides vacuum.
The physical, chemical, optical, and thermal Homes on the α -BBO are just like These of the BBO crystals, however the α -BBO isn't going to show the nonlinear optical Attributes due to the central symmetry of its crystal framework.
When pulse lengths are between 1 ns and 1 µs, laser-induced hurt can happen both as a result of absorption or perhaps a dielectric breakdown (hence, a user need to Check out both equally CW and pulsed LIDT). Absorption is possibly because of an intrinsic property of the optic or as a consequence of area irregularities; Consequently LIDT values are only valid for optics meeting or exceeding the surface high-quality requirements provided by a manufacturer.
The temporal stroll-off with the slower pulse with regard to the quicker can be a substantial portion of the heart beat period. This is illustrated in Determine 22.
The Uncooked materials, usually a combination of barium carbonate and boric acid, are positioned inside a platinum crucible and heated till they soften. The temperature is then little by little diminished, making it possible for the BBO crystal to type about many weeks. The crystal is then extracted, cut into the specified form, and polished to realize a higher-quality optical area.
When evaluating an LIDT specified for any pulsed laser in your laser, it is important to grasp the subsequent:
A advised guideline for focusing femtosecond laser pulses right into a nonlinear crystal is to take care of a Rayleigh array that is certainly at the very least a number of situations extended as opposed to length with the SHG crystal. This minimizes the chance of harming the crystal, and also minimizes the detrimental results of spatial section mismatch and spatial (Poynting vector) walk-off.
This is especially essential in Organic and clinical exploration the place particular compounds or cells are tagged with fluorescent markers. get more info The 266nm light can excite these markers, earning them stick out Obviously against a qualifications, thereby facilitating detailed Investigation.