Rumored Buzz on a-BBO Crystal
Rumored Buzz on a-BBO Crystal
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Figure fifteen displays the orientation of γ in a very laboratory frame rotation on the crystal. In this example situation, the nonlinear crystal is mounted within an RSP1 rotation mount on top of an RP01 rotation phase. Improvements in γ and θ alter the orientation of the optic axis, . In cases like this, changes in γ are used to align Using the horizontal aircraft and among the list of principle common axes vertically. To get a vertically polarized enter beam, this orientation allows the rotation phase for use to adjust θ.
The 266nm wavelength delivers unique interactions that other wavelengths can’t, making it indispensable for detecting and finding out selected compounds.
The place of your eco-friendly curve will depend on θ. In such a case, the angle θ has long been tuned to offer a refractive index for 515 nm light-weight that matches the refractive index for 1030 nm light-weight. This tuning angle is for that reason optimized for Variety-I SHG period matching along with a elementary-frequency enter beam of 1030 nm.
A: Of course, BBO crystals show spectacular thermal steadiness, building them well suited for purposes with various temperatures.
From a ray-product point of view, the propagation direction defines the orientation from the central (Main) ray in Figure 23. The SHG process is afflicted with the range of angles about which incident gentle propagates, for the reason that light that isn't parallel on the chief ray has decreased period-matching relative towards the Main ray.
Now Look at the most energy density to that that's specified as the LIDT for your optic. In the event the optic was analyzed in a wavelength other than your operating wavelength, the damage threshold should be scaled correctly.
Humidity might cause drinking water absorption about the crystal surface, which can degrade its optical performance. The standard of the incident gentle, like its wavelength, intensity, and polarization, can also impact the overall performance of BBO crystals in numerous applications.
Even so, though BBO crystals can function at room temperature, Serious temperatures should really even now be avoided as they will impact the crystal’s period-matching conditions and perhaps bring about damage.
Such as, contemplate a elementary pulse propagating around a provided crystal thickness. In the event the temporal stroll-off is bigger compared to the length of the basic pulse, this pulse will even have a spectral bandwidth that drastically exceeds the spectral width of your reference pulse. A common rule for limiting the harmful effects connected with both of those Actual physical effects is to select a crystal thickness that boundaries the elemental and second harmonic temporal walk-off to no more than the length of the basic pulse.
Consequently, the 2nd harmonic pulse spectrum, demonstrated on the proper, has a spectral width about similar to the ideal circumstance. Ideally, each individual frequency in the basic pulse spectrum might be at the same time period matched.
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For beams with a superior PRF both of those the average and peak powers has to be compared to the equivalent CW ability. Also, for extremely clear supplies, There's little to no fall within the LIDT with raising PRF.
A recommended guideline for concentrating femtosecond laser pulses into a nonlinear crystal is to maintain a Rayleigh vary that is definitely at the least numerous times for a longer period when compared to the duration in the SHG crystal. This minimizes the chance of detrimental the crystal, in addition to cuts down the adverse effects of spatial stage mismatch and spatial (Poynting vector) stroll-off.
Additionally, the structural and here compositional characteristics of BBO present it with amazing thermal security and resistance in opposition to environmental challenges.