a-BBO Crystal - An Overview
a-BBO Crystal - An Overview
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The fundamental subject now driving the Type-I SHG system may be the Eoγ part of your incident discipline. At γ = ninety°, there can be zero SHG output, since the drive industry Eoγ = 0.
β-BBO Crystal—a extensively made use of nonlinear crystal for frequency conversion while in the ultraviolet, noticeable and in the vicinity of-infrared
The Rayleigh vary quantifies the space, calculated with the beam midsection, more than which the beam diameter is about continuous. The shorter the Rayleigh vary, the much larger the speed of divergence.
In quasi-phase matching, the crystal material is “poled�?to own up and down domains to counteract the phase-mismatch of the fabric, where by the poling time period is certain for the wavelengths of interaction.
The 266nm technology makes sure that these interactions are finely tuned, allowing researchers to glean insights with Increased precision. Regardless of whether it’s in finding out complicated molecules, figuring out the Homes of latest products, or in environmental checking, the BBO crystal’s power to produce 266nm mild amplifies the depth and accuracy of spectroscopic scientific studies.
The efficiency of the SHG system decreases significantly as the fundamental beam diverges from its concentrate, Considering that the pulse Strength is distributed throughout a bigger beam cross area.
Though the above process gives an excellent general guideline for LIDT values, be sure to Call Tech Support if your wavelength differs from the required LIDT wavelength. If the electric power density is below the adjusted LIDT of your optic, then the optic should really work for your software.
The angular content of a focused beam could be visualized by tracing rays in the lens to the focal location. Every ray drawn within the lens to some tightly concentrated place (Figure 23) helps make a different angle (ψ) with the chief ray, plus the number of angles raises with the NA. Because the number of angles will increase over and above the reference NA filter (or angular area apodization filter width), the period-matching with the rays beyond the filter width diminishes for that reason cutting down the SHG conversion effectiveness of People rays.
Considering that the refractive index won't differ linearly with frequency in dispersive crystals like β-BBO, it is actually impossible to optimally stage match each frequency in the input pulse's spectral assortment With all the corresponding next harmonic frequency here inside the created pulse.
A5: Of course, BBO crystals have excellent thermal stability and can keep their Houses at room temperature. Which means they can be used in a wide array of environments without the need of requiring Unique temperature control.
The team velocity and also the period velocity aren't equivalent, meaning the sine wave with the copyright along with the envelope of the pulse transfer as a result of optical media at distinct speeds.
This wonderful-tuning capability means that BBO crystals can cater to equally generic and highly specialized desires with equal finesse.
A encouraged guideline for focusing femtosecond laser pulses into a nonlinear crystal is to take care of a Rayleigh selection which is a minimum of several periods more time compared to the duration on the SHG crystal. This minimizes the chance of detrimental the crystal, in addition to lessens the unfavorable outcomes of spatial phase mismatch and spatial (Poynting vector) stroll-off.
The spectrally narrowed SHG pulse spectrum is alleged for being apodized, due to the fact an effect of the fundamental pulse exceeding the utmost input bandwidth Restrict is definitely the removal of the highest and most affordable frequencies in the SHG pulse spectrum.