Examine This Report on KGW Crystal
Examine This Report on KGW Crystal
Blog Article
Investigating tumor perfusion by hyperpolarized (thirteen) C MRI with comparison to traditional gadolinium contrast-Increased MRI and pathology in orthotopic human GBM xenografts.
We use cookies to tell apart you from other people also to supply you with an improved practical experience on our Web sites. Close this message to accept cookies or Learn the way to manage your cookie options.
A not-for-financial gain Business, IEEE is the earth's greatest specialized Specialist Firm focused on advancing technologies for the advantage of humanity.
In addition to its use like a Raman crystal, KGW is additionally Utilized in other optical applications, like in laser techniques and as a scintillator in health-related imaging.
In distinction, the seed laser is often amplified to around one mJ underneath the orthogonal orientation configuration.
The calculated Slice-off wavelengths in the short-wavelength side are in keeping with the overall trend of blue-shifted spectral broadening within the bandgap of nonlinear substance. All the nonlinear elements created acceptable red-shifted spectral broadenings underneath circumstances of best pump pulse energies, with the largest red-shift exceeding 2000 nm measured in GGG crystal. Our final results disclosed that GGG and BGO (which also experienced the lowest supercontinuum era threshold) offer tough, optical damage-absolutely free functionality in a laser repetition charge of 200 kHz, suggesting that these elements are good options to YAG and KGW for minimal threshold, substantial regular electric power supercontinuum era inside the around- and quick-wave infrared spectral ranges. We also demonstrated that scintillating Houses of bulk components may be conveniently examined inside the filamentation routine, by way of multiphoton excitation utilizing close to-infrared femtosecond laser pulses.
Many techniques are actually adopted to unravel this issue. An acousto-optical programmable dispersive filter could be utilized to modulate the seed’s spectrum to suppress the achieve-narrowing result[
Lastly, we investigated the lengthy-expression performances of SC generation in crystal samples underneath best pumping ailments at increased laser repetition costs. In doing so, the crystal samples weren't translated and retained inside a stationary posture with respect to the pump beam over the overall measurement. The examples illustrating robust extensive-expression performances of SC era in KGW and YAG crystals at high laser repetition charges may very well be uncovered somewhere else. Extra specifically, stable effectiveness of KGW crystal at two MHz pulse repetition price less than extremely equivalent pump beam concentrating geometry was reported recently30, Whilst YAG crystal shown steady overall performance for several hrs at 200 kHz pulse repetition charge even with incredibly limited focusing of the pump beam (NA=0.085)32. The long-phrase performance assessments in LSO, LYSO and YSO unveiled gradual narrowing in the SC spectra around the long-wavelength facet that transpired just after a particular publicity time and will be attributed to your optical degradation of such materials. For example, in LSO, the onset of spectral narrowing was noticed after (sim 20) minutes at a laser repetition amount of 10 kHz, though at a laser repetition fee of 20 kHz, steady SC technology performance was observed just for about two min.
The actual spectra have been reconstructed by correcting the calculated spectra using an account to the filter transmission features and for that sensitivity features on the spectrometers at the data put up-processing stage. The spectral dynamics in Every single sample was measured by fine tuning the pump pulse Electricity with a pc-controlled attenuator which was built-in in the laser method. Thermal energy meter EM (Ophir 3A-PF-12) was used to measure the SC Electrical power which was thereafter utilized to estimate the spectral Electricity density of your SC radiation. Many of the measurements were being performed without any translation of your sample with regard into the pump beam.
The 2-pump laser could offer you approximately 120 W ability. Around 60% of the most pump electricity was utilized in our experiment contemplating the lower performance with the dichroic mirrors. Under this dual-crystal configuration, our cavity supports a a hundred W pump electric power input, as mentioned in Portion two.2. Higher-top quality dichroic mirrors will likely be utilized Down the road, and laser pulses might be stretched to a longer pulse period.
While BGO, GGG, YSO, LSO and LYSO once in a while serve as laser hosts37, They can be mostly identified as productive scintillators, whose scintillation Houses are researched really well38. However, the nonlinear optical Attributes of those crystals and so their likely to serve as nonlinear elements for SC era especially, and another experiments relating to nonlinear propagation of extreme femtosecond laser pulses, remain incredibly badly examined. Thus far, GGG, LT23,twenty five and YSO24 had been only sketchily analyzed for SC generation with Ti:sapphire laser pumping, even so, to the top of our know-how, Not one of the investigated products had been examined with Yb-laser pumping, specifically for what fears their functionality at extremely superior (tens to countless kHz) pulse repetition charges.
Considering the fact that its discovery in 19701,two, the condition from the art of supercontinuum (SC) generation in bulk strong-point out resources has achieved a substantial volume of maturity thanks to huge progress of ultrafast laser resources and fundamental idea of the fundamental Bodily processes3,4. The complexity of physical effects fundamental SC technology is unveiled inside the framework of femtosecond filamentation, and that is a common phenomenon arising from nonlinear propagation of femtosecond laser pulses in transparent materials5. In more sensible terms, the attainable spectral extent of SC radiation depends on the material Houses, for example linear and nonlinear indexes of refraction and energy bandgap, which together with the laser wavelength outline the critical electric power for self-concentrating (that has to become exceeded for a light-weight filament to kind) and clamping intensity of a lightweight filament (and that is proportional to the buy of multiphoton absorption), respectively.
The scattered photons have a different wavelength and Strength than the incident photons, which makes a Raman spectrum.
Both of those energies are marked from the dashed strains as well as their values are labeled within the plots. The identical capabilities had been also observed in KGW and YAG here crystals, whose spectral broadening dynamics are demonstrated to get a comparison in Fig. four.