BBO Crystal for Dummies
BBO Crystal for Dummies
Blog Article
This short article dives deep into the advantages and special Qualities of BBO crystal and its paramount significance in successful frequency doubling and harmonics technology at 266nm.
The issue that arises when working with ultrashort pulses for next harmonic technology (SHG) is usually that shorter pulses have more substantial bandwidths, but The perfect section-matched situation can be attained for only an individual basic wavelength at a time. Due to this, the quality of the phase match might be noticeably worse towards the spectral edges of broad-bandwidth pulses.
These Houses make BBO crystals hugely appealing in many applications, from laser frequency conversion to electro-optic modulation. Their broad transparency selection lets them to operate with a broad array of laser wavelengths, when their significant destruction threshold makes certain they will cope with superior-power laser beams with no degradation.
Take note that even when the nominal intensity is down below the nominal problems threshold, there may be challenges as a consequence of fluctuations from the beam electric power or regional intensity (e.g., if a beam profile has “very hot places�?, or as a result of isolated defects within a crystal, which happen to be a lot more delicate compared to normal crystal materials.
The next harmonic light-weight is then polarized parallel to your plane. Angle tuning adjusts θ and is also done by rotating the crystal within the Y-axis.
This sort of resilience makes sure that its nonlinear Houses aren't very easily compromised, which makes it a favorite in environments exactly where regularity and reliability are paramount.
The second harmonic frequency wave is generated as an extraordinary wave, which can be polarized orthogonal to the basic-frequency everyday wave.
Operation of nonlinear crystals at temperatures below space temperature (to obtain period matching) is usually problematic, as it may cause condensation of h2o about the crystal surfaces If your surrounding air isn't very dry.
In quasi-period matching, the crystal product is “poled�?to own up and down domains to counteract the stage-mismatch of the material, where the poling time period is precise to the wavelengths of conversation.
The next is often a standard overview of how laser induced destruction thresholds are measured And just how the values can be utilized in determining the appropriateness of the optic for a provided software. When choosing optics, it is vital to know the Laser Induced Injury Threshold (LIDT) from the optics being used. The LIDT for an optic considerably depends upon the kind of laser that you are utilizing. Continuous wave (CW) lasers normally result in harm from thermal outcomes (absorption both during the coating or while in the substrate).
The Uncooked elements, commonly a mix of barium carbonate and boric acid, are positioned within a platinum crucible and heated right until they soften. The temperature is then step by step decreased, letting the BBO crystal to type above several months. The crystal is then extracted, cut into the desired condition, and polished to accomplish a significant-high quality optical floor.
Though the check results are only consultant of 1 coating operate, Thorlabs specifies problems threshold values that account for coating variances.
The magnitude on the successful nonlinear coefficient relies on read more the nonlinear tensor components and over the used period-matching configuration. A higher nonlinearity is essential significantly if the achievable optical intensities are reduced.
Even if the crystal material or coating is just not delicate to water, compact drinking water droplets may possibly target laser radiation more tightly than underneath regular operation, and therefore damage the crystal material.