اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدDesign, production and characterization of mirrors for ultra-broadband, high-finesse enhancement cavities
44
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
To enable the enhancement of few-cycle pulses in high-finesse passive optical resonators, a novel complementary-phase approach is considered for the resonator mirrors. The design challenges and first experimental results are presented.
قيم البحث
اقرأ أيضاً
We report on the optical characterization of an ultra-high diffraction efficiency grating in 1st order Littrow configuration. The apparatus used was an optical cavity built from the grating under investigation and an additional high reflection mirror
. Measurement of the cavity finesse provided precise information about the gratings diffraction efficiency and its optical loss. We measured a finesse of 1580 from which we deduced a diffraction efficiency of (99.635$pm$0.016)% and an overall optical loss due to scattering and absorption of just 0.185 %. Such high quality gratings, including the tool used for their characterization, might apply for future gravitational wave detectors. For example the demonstrated cavity itself presents an all-reflective, low-loss Fabry-Perot resonator that might replace conventional arm cavities in advanced high power Michelson interferometers.
The dynamics of nanosystems in solution contain a wealth of information with relevance for diverse fields ranging from materials science to biology and biomedical applications. When nanosystems are marked with fluorophores or strong scatterers, it is
possible to track their position and reveal internal motion with high spatial and temporal resolution. However, markers can be toxic, expensive, or change the objects intrinsic properties. Here, we simultaneously measure dispersive frequency shifts of three transverse modes of a high-finesse microcavity to obtain the three-dimensional path of unlabeled SiO$_2$ nanospheres with $300$$mathrm{mu}$s temporal and down to $8$nm spatial resolution. This allows us to quantitatively determine properties such as the polarizability, hydrodynamic radius, and effective refractive index. The fiber-based cavity is integrated in a direct-laser-written microfluidic device that enables the precise control of the fluid with ultra-small sample volumes. Our approach enables quantitative nanomaterial characterization and the analysis of biomolecular motion at high bandwidth.
High-power lasers have numerous scientific and industrial applications. Some key areas include laser cutting and welding in manufacturing, directed energy in fusion reactors or defense applications, laser surgery in medicine, and advanced photolithog
raphy in the semiconductor industry. These applications require optical components, in particular mirrors, that withstand high optical powers for directing light from the laser to the target. Ordinarily, mirrors are comprised of multilayer coatings of different refractive index and thickness. At high powers, imperfections in these layers lead to absorption of light, resulting in thermal stress and permanent damage to the mirror. Here we design, simulate, fabricate, and demonstrate monolithic and highly reflective dielectric mirrors which operate under high laser powers without damage. The mirrors are realized by etching nanostructures into the surface of single-crystal diamond, a material with exceptional optical and thermal properties. We measure reflectivities of greater than 98% and demonstrate damage-free operation using 10 kW of continuous-wave laser light at 1070 nm, with intensities up to 4.6 MW/cm2. In contrast, at these laser powers, we observe damage to a standard dielectric mirror based on optical coatings. Our results initiate a new category of broadband optics that operate in extreme conditions.
A microwave ultra-broadband polarization-independent metamaterial absorber is demonstrated. It is composed of a periodic array of metal-dielectric multilayered quadrangular frustum pyramids. These pyramids possess resonant absorption modes at multi-f
requencies, of which the overlapping leads to the total absorption of the incident wave over an ultra-wide spectral band. The experimental absorption at normal incidence is above 90% in the frequency range of 7.8-14.7GHz, and the absorption is kept large when the incident angle is smaller than 60 degrees. The experimental results agree well with the numerical simulation.
It is prohibitively expensive to deposit customized dielectric coatings on individual optics. One solution is to batch-coat many optics with extra dielectric layers, then remove layers from individual optics as needed. Here we present a low-cost, sin
gle-step, monitored wet etch technique for reliably removing (or partially removing) individual SiO$_2$ and Ta$_2$O$_5$ dielectric layers, in this case from a high-reflectivity fiber mirror. By immersing in acid and monitoring off-band reflected light, we show it is straightforward to iteratively (or continuously) remove six bilayers. At each stage, we characterize the coating performance with a Fabry-P{e}rot cavity, observing the expected stepwise decrease in finesse from 92,000$pm$3,000 to 3,950$pm$50, finding no evidence of added optical losses. The etch also removes the fibers sidewall coating after a single bilayer, and, after six bilayers, confines the remaining coating to a $sim$50-$mu$m-diameter pedestal at the center of the fiber tip. Vapor etching above the solution produces a tapered pool cue cladding profile, reducing the fiber diameter (nominally 125 $mu$m) to $sim$100 $mu$m at an angle of $sim$0.3$^circ$ near the tip. Finally, we note that the data generated by this technique provides a sensitive estimate of the layers optical depths. This technique could be readily adapted to free-space optics and other coatings.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
