The crystal axis is c. The chief ray is parallel into the course used to evaluate the tuning angle (θ), and that is optimized all through section matching. Conversion effectiveness is optimized for rays parallel for the Main ray and even worse for rays at more substantial angles (ψ) to your Main ray.
Unfortunately, it can be very hard to match the LIDT specification of the optic to your laser. You will find several regimes through which a pulsed laser can hurt an optic and this is predicated on the laser's pulse length. The highlighted columns inside the table beneath outline the pertinent pulse lengths for our specified LIDT values.
There are two velocities that determine the propagation of light in optical media: the phase and team velocities. The section velocity will be the velocity in the provider, the oscillation of the electrical industry, and the velocity which is matched involving the fundamental and second harmonic frequencies for period matching. The phase velocity relative to the velocity of light in a vacuum is outlined because of the index of refraction.
Beam diameter can be imperative that you know when comparing hurt thresholds. Whilst the LIDT, when expressed in units of J/cm², scales independently of spot size; huge beam dimensions are more likely to illuminate a larger amount of defects which can lead to better variances inside the LIDT [four].
Finally, the vast-angle tunability of BBOs facilitates customization like by no means just before. Depending upon the unique prerequisites of an software, the crystal might be adjusted with precision, ensuring which the output is usually optimized.
). This spatial focusing constraint about the SHG procedure will frequently cause the crystal length normally being a lot less than the Rayleigh here selection of the enter focused pulse.
Though the above mentioned course of action provides a good guideline for LIDT values, be sure to Call Tech Assistance Should your wavelength is different from the desired LIDT wavelength. Should your electricity density is below the modified LIDT in the optic, then the optic ought to operate for the application.
It is often important to concentration the incident gentle inside the crystal for SHG programs, given that efficient era of 2nd harmonic light-weight necessitates high peak intensities, which include 109 W/cm2. When applying femtosecond pulses with average energies from the nanojoule array, acquiring the needed peak intensities can need smaller focal spots.
This home sets it besides linear optical supplies that don’t change the frequency of light passing as a result of them. This type of distinguishing feature forms the inspiration for any myriad of purposes that BBO can provide.
The SHG mild is polarized in the XZ aircraft and it is orthogonal to equally the Eo along with the k-vector. Instead of decompose the polarization of your SHG light-weight into Ex and Ez elements, the electrical area is often described as a unprecedented wave (E'e). The refractive index for this remarkable wave, n'e, modifications to be a operate of θ. n'e(θ) might be calculated using the equation in Determine 13. The ellipse defining the extraordinary index of refraction for a function of θ can be a conic portion in the index ellipsoid.
Each broad-bandwidth pulses and temporal stroll-off bring about a discount within the conversion effectiveness, together with worsen the optical high-quality of the second harmonic pulses. The appropriate crystal thickness needs to be picked to minimize the two consequences.
This characteristic interprets to diminished want for considerable thermal management systems, all over again accentuating Charge discounts and program simplicity.
The 266nm generation refers back to the production of ultraviolet gentle which has a wavelength of 266 nanometers.
The problem that occurs when applying ultrashort pulses for second harmonic generation (SHG) is shorter pulses have more substantial bandwidths, but The best section-matched ailment can be accomplished For less than an individual elementary wavelength at any given time. As a consequence of this, the standard of the section match is usually considerably worse towards the spectral edges of broad-bandwidth pulses.