The 2-Minute Rule for a-BBO Crystal
The 2-Minute Rule for a-BBO Crystal
Blog Article
Determine 15 demonstrates the orientation of γ in a very laboratory body rotation from the crystal. In this example scenario, the nonlinear crystal is mounted within an RSP1 rotation mount in addition to an RP01 rotation stage. Adjustments in γ and θ change the orientation with the optic axis, . In such a case, adjustments in γ have already been utilized to align While using the horizontal aircraft and one of the basic principle everyday axes vertically. For your vertically polarized enter beam, this orientation makes it possible for the rotation phase for use to adjust θ.
The 2 frequencies' phase velocities are equivalent once they possess the very same refractive index. The refractive indices for both of these frequencies are commonly not equal, due to the fact all media other than vacuum are dispersive. Consequently a fabric's refractive index depends on the light's frequency.
There are two velocities that define the propagation of light in optical media: the phase and team velocities. The period velocity is definitely the speed of the copyright, the oscillation of the electrical field, as well as the velocity that is definitely matched in between the fundamental and 2nd harmonic frequencies for period matching. The phase velocity relative for the velocity of light within a vacuum is defined through the index of refraction.
A: A large injury threshold guarantees the crystal can deal with a lot more power with no degrading, bringing about lengthier lifespan and steady effectiveness.
No matter if it’s in the event of extra efficient lasers, the exploration of quantum phenomena, or maybe the creation of latest optical products, BBO crystals will without doubt carry on to Engage in a pivotal position.
The efficiency from the SHG method decreases significantly as the elemental beam diverges from its focus, Because the pulse Strength is distributed across a larger beam cross portion.
Sometimes, the mismatch is often compact. For instance, any time a β-BBO crystal is accustomed to frequency double 1550 nm gentle and supply 775 nm gentle, the group velocity mismatch is only some femtoseconds for every millimeter.
The Bodily, chemical, optical, and thermal Attributes with the α -BBO are comparable to those of the BBO crystals, nevertheless the α -BBO would not show the nonlinear optical Homes as a result of central symmetry of its crystal composition.
Because the refractive index will not differ linearly with frequency in dispersive crystals like β-BBO, it really is not possible to optimally section match each individual frequency from the input pulse's spectral range Along with the corresponding second harmonic frequency during the produced pulse.
The SHG light is polarized within the XZ airplane and is also orthogonal to both the Eo as well as k-vector. As an alternative to decompose the polarization from the SHG gentle into Ex and Ez components, the electric field is typically referred to as an extraordinary wave (E'e). The refractive index for this amazing wave, here n'e, adjustments like a perform of θ. n'e(θ) is often calculated using the equation in Determine 13. The ellipse defining the incredible index of refraction like a functionality of θ is a conic area of the index ellipsoid.
The elemental source could be the dye laser radiation pumped by the next harmonic of a Q-switched Nd: YAG laser. A walk-off compensated configuration With all the BBO crystal pair has enabled us to appreciate this kind of high conversion performance inside the interaction.
For beams which has a substantial PRF both equally the common and peak powers should be as compared to the equal CW ability. Additionally, for highly transparent components, There is certainly tiny to no fall from the LIDT with increasing PRF.
A suggested guideline for focusing femtosecond laser pulses right into a nonlinear crystal is to take care of a Rayleigh selection that is certainly at the very least numerous times for a longer period when compared to the size in the SHG crystal. This minimizes the possibility of harmful the crystal, as well as minimizes the destructive outcomes of spatial section mismatch and spatial (Poynting vector) stroll-off.
This is particularly essential in biological and medical research where unique compounds or cells are tagged with fluorescent markers. The 266nm light-weight can excite these markers, generating them get noticed clearly in opposition to a track record, thereby facilitating in-depth Investigation.