The crystal axis is c. The Main ray is parallel to your course used to measure the tuning angle (θ), and that is optimized in the course of period matching. Conversion efficiency is optimized for rays parallel into the chief ray and even worse for rays at greater angles (ψ) into the chief ray.
β-BBO Crystal—a greatly utilised nonlinear crystal for frequency conversion in the ultraviolet, seen and around-infrared
Howdy, thanks for calling Thorlabs. The wavelength ranges from the antireflective coatings on these β-BBO crystals align With all the respective wavelength bands that these crystals are optimized for. Requests for customizations might be produced by achieving out to us at [email protected]
The section matching angle might be modified by rotating the crystal within the y axis. An adjustment that is usually inside of a several levels can either enhance the effectiveness with the crystal during the set up or match Yet another basic frequency within the crystal's working array.
The Strength density of one's beam really should be calculated when it comes to J/cm2. The graph to the correct exhibits why expressing the LIDT being an Electrical power density supplies the very best metric for brief pulse sources. Within this routine, the LIDT specified being an Electricity density could be placed on any beam diameter; one won't have to compute an altered LIDT to regulate for adjustments in spot sizing.
Thorlabs expresses LIDT for CW lasers like a linear electrical power density measured in W/cm. Within this regime, the LIDT provided being a linear electric power density can be placed on any beam diameter; a single isn't going to need to compute an modified LIDT to regulate for modifications in spot dimension, as shown through the graph to the appropriate. Common linear electrical power density might be calculated utilizing the equation beneath.
The spatial stroll-off angle depends on the size on the beam as well as crystal length. Even though the angle is usually considerable, it is often smaller, typically within the buy of 10 mrad, and will be neglected.
Some companies' SHG crystals, which includes Thorlabs', give in the vicinity of-section-matched circumstances for Generally incident enter gentle for the specified essential frequency. These producers polish the faces on the SHG crystals these kinds of the angle amongst the Commonly incident gentle along with the optic axis would be the stage-matched angle for the specified frequency.
Assuming a crystal of the supplied thickness, it is achievable to outline a reference pulse having a spectral range that may be the utmost which can be sufficiently stage matched. This spectral bandwidth limitation will also be thought of in terms of an SHG spectral filter whose passband will depend on both of those the specific crystal and the heart beat's Middle frequency. Frequencies beyond this filter’s passband will likely be turned down from undergoing the SHG course of action.
Therefore, the 2nd harmonic pulse spectrum, proven on the right, provides a spectral width about similar to The perfect case. Ideally, each frequency in the fundamental pulse spectrum would be concurrently section matched.
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When selecting an SHG crystal, the heartbeat period of your laser source should be taken into consideration. A mismatch involving the period and crystal thickness will lead to SHG pulses lengthier in time and narrower in spectral material than doable less than ideal conditions.
When an enter pulse's spectral range is equivalent to or narrower compared to the reference pulse, the generated second harmonic pulse features a duration which is shorter by a factor of 1/√two and a spectral width that may be broader by an element of √2.
Lastly, spectroscopy, the review of interactions among issue and electromagnetic radiation, drastically website benefits through the 266nm generation. In spectroscopic programs, various wavelengths of light interact in a different way with materials, giving a spectrum that could be analyzed to determine the material’s properties or composition.