a-BBO Crystal - An Overview
a-BBO Crystal - An Overview
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The significant hurt threshold of BBO crystals is particularly vital in environments the place large-depth lasers are classified as the norm. Standard elements could falter, degrade, or even split less than such intensities.
A2: Indeed, extended exposure to humidity can degrade the optical performance of BBO crystals. Humidity can result in drinking water absorption to the crystal surface area, which often can impact its optical Houses.
As a way to use the specified CW problems threshold of the optic, it's important to be aware of the next:
Beam diameter can also be imperative that you know when comparing destruction thresholds. While the LIDT, when expressed in models of J/cm², scales independently of place sizing; large beam sizes usually tend to illuminate a bigger variety of defects which may lead to larger variances within the LIDT [4].
Any contamination can degrade the optical efficiency on the crystal and probably result in destruction below high laser energy. When storing BBO crystals, they need to be placed inside of a protecting case to circumvent Bodily problems and dust accumulation.
Make sure you Notice that We have now a buffer crafted in between the required problems thresholds on the internet and the checks which We've completed, which accommodates variation involving batches. On ask for, we can provide individual test data as well as a testing certificate.
Determine 18: The standard and incredible refractive indices of β-BBO vary with frequency and wavelength as a consequence of a material home known as dispersion. Dispersion exists in all media other than vacuum.
When an optic is destroyed by a continual wave (CW) laser, it is normally mainly because of the melting of the area as a result of absorbing the laser's Strength or harm to the optical coating (antireflection) [one]. Pulsed lasers with pulse lengths lengthier than 1 µs is usually dealt with as CW lasers for LIDT conversations.
For the reason that refractive index isn't going to differ linearly with frequency in dispersive crystals like β-BBO, it's impossible to optimally section match each frequency in the enter pulse's spectral assortment While using the corresponding 2nd harmonic frequency within the created pulse.
The temporal wander-off of the slower pulse with respect towards the more quickly might be a substantial fraction of the heartbeat length. This really is illustrated in Figure 22.
The team velocity and the period velocity aren't equivalent, meaning the sine wave on the provider and the envelope of the heartbeat shift through optical media at diverse speeds.
When picking an SHG crystal, the heart beat duration from the laser supply need to be taken into account. A mismatch concerning the duration and crystal thickness will bring about SHG pulses for a longer period in time and narrower in spectral content than feasible below excellent ailments.
When an enter pulse's spectral selection is equivalent to or narrower compared to the reference website pulse, the produced second harmonic pulse features a duration that's shorter by an element of one/√two plus a spectral width that is certainly broader by a factor of √2.
This is especially essential in biological and healthcare research where by precise compounds or cells are tagged with fluorescent markers. The 266nm gentle can excite these markers, producing them stand out Evidently against a history, therefore facilitating comprehensive Assessment.