The smart Trick of BBO Crystal That Nobody is Discussing
The smart Trick of BBO Crystal That Nobody is Discussing
Blog Article
One example is, think about a elementary pulse propagating over a specified crystal thickness. If the temporal stroll-off is bigger compared to period of the fundamental pulse, this pulse will even have a spectral bandwidth that tremendously exceeds the spectral width of the reference pulse. A basic rule for restricting the detrimental results connected to both equally Actual physical results is to choose a crystal thickness that restrictions the elemental and 2nd harmonic temporal stroll-off to no more than the length of the elemental pulse.
In many conditions, a nonlinear crystal employed for nonlinear frequency conversion has an incredibly extensive lifetime, and that is for a longer period than that of the whole laser procedure. The crystal product is essentially not modified in the course of operation. Having said that, a lowered crystal life time can manifest less than different circumstances:
Optical transmission (OT): We employ OT to measure the optical passage spectrum of our merchandise in excess of their openness array. We warranty our solutions are devoid of absorption bands or scattering losses as a result of pollutants or difficulties.
So as to use the required CW hurt threshold of an optic, it's important to learn the following:
linear absorption, which could lead to heating at higher optical electrical power stages, so that the period matching is disturbed, and thermal lensing may manifest
The calculation above assumes a uniform beam depth profile. You should now consider hotspots inside the beam or other non-uniform intensity profiles and approximately compute a maximum ability density.
The 2nd harmonic frequency wave is produced as an extraordinary wave, which can be polarized orthogonal to the fundamental-frequency common wave.
Determine fifteen demonstrates the orientation of γ in the laboratory frame rotation on the crystal. In this example situation, the nonlinear crystal is mounted in an RSP1 rotation mount in addition to an RP01 rotation stage. Alterations in γ and θ modify the get more info orientation of your optic axis, . In such cases, adjustments in γ are actually accustomed to align Together with the horizontal plane and one of the theory regular axes vertically. For any vertically polarized enter beam, this orientation lets the rotation stage for use to adjust θ.
It’s important to stay away from working with abrasive supplies or solid solvents, as these can scratch or if not harm the crystal’s floor. Frequent cleansing may help manage the crystal’s optical performance and prolong its lifespan.
In practice, γ is nonzero when the polarization states of light in a very laboratory reference body will not be matched on the intrinsic principal axes in the crystal frame. To orient The 2 reference frames alongside one another, e.g. the vertically polarized mild through the laser on the optical desk is parallel to inside the crystal, we mount the nonlinear crystal in the rotation stage to finely change γ to zero, very first by eye using the markings on the housing and after that more, if important, using the SHG output electric power as feed-back.
When evaluating an LIDT specified for a pulsed laser on your laser, it is important to understand the following:
BBO nonlinear crystal is usually a destructive uniaxial crystal. It offers phase matching for numerous 2nd-get interactions Just about around its full transparency vary. This transparency ranges from 185 nm to three.3 µm, as inferred from transmittance measurements utilizing crystal samples of a few mm thickness.
Therefore, the next harmonic pulse spectrum, proven on the best, has a spectral width somewhere around the same as The best situation. Preferably, each individual frequency in the elemental pulse spectrum could well be at the same time stage matched.
Massive angular stroll-off BBO crystals Use a significant angular stroll-off that triggers spatial splitting amongst a variety of polarization elements of sunshine when circulating with a BBO crystal.