Thermo-optic refraction in MoS2 medium for “Normally on” all optical switch

The temporally switchable optical mode conversion is crucial for optical communication and computing applications. This research demonstrates such optically switchable mode converter driven by thermo-optic refraction. The MoS2 nanofluid is used as a medium where the thermal microlens is created by a focused laser beam (pump). The convective thermal plume generated above the focal point of the pump beam within the nanofluid acts as an astigmatic thermal lens. It is discovered that mode conversion of the Laguerre-Gaussian (LG) to the Hermite-Gaussian (HG) beam (vice versa) takes place upon passing through the thermal lens. The topological charge of the LG beam can be easily determined using the proposed mode converter. The mode transformation is explained theoretically as the Fourier components of the LG beam undergoing different optical paths while propagating through the convective plume.

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“…1) due to the upward convective flow of the heated nanofluid. Details on thermal lens formation can be found in our previous article [24].…”

Section: Resultsmentioning

confidence: 99%

“…The nanofluid consists of nanoflakes of MoS2 dispersed in 3%w/w Polyvinylpyrrolidone (PVP) polymer solution. The material preparation is explained in our previous article [24]. UV-Vis absorption spectrum showed that MoS2 nanofluid has broadband absorption in visible region (400-700nm).…”

Section: Sample Preparation and Characterizationmentioning

confidence: 99%

Thermo-optic refraction based switchable optical mode converter

Shetty

Максимов

Babu

et al. 2021

Journal of Quantitative Spectroscopy and Radiative Transfer

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“…To achieve a stable dispersion, MoS2 nanoflakes were dispersed in 3% w/w Polyvinylpyrrolidone (PVP) polymer solution. The detailed method of MoS2 nanofluid preparation is given in article [18]. UV-Vis spectra of MoS2 nanofluid indicated broadband absorption in visible region(400nm-700nm).…”

Section: Materials Synthesis and Characterizationmentioning

confidence: 99%

“…Where 𝐷 = 𝐾/𝜌𝑐 𝑝 is thermal diffusivity of nanofluid, 𝐾 = 0.1769 𝑊/𝑚𝐾 is thermal conductivity of nanofluid, 𝜌 = 789 𝐾𝑔/𝑚 3 is density of nanofluid, 𝑐 𝑝 = 2440 𝐽 𝑘𝑔.𝐾 is specific heat of nanofluid, 𝛼 = 68.097𝑚 −1 is absorption coefficient of nanofluid at 650nm [18].…”

Section: Thermo-optic Refraction Interferometer (Tori)mentioning

confidence: 99%

Vortex phase deterioration common-path interferometry

Shetty

Hemalatha

Babu

et al. 2023

J. Opt.

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Common path interferometers (CPI) are significant due to their compactness and vibration resistance. The usual challenge in CPI would arise due to a very small separation between reference and sample beams, where sending a reference beam through a sample is considered as a limitation. But this limitation also makes it difficult to probe the interaction of beams with material as a function of their phase structure. This study can pave the way for a new kind of interferometry that can provide unique phase signatures to study the sample. The paper proposes and demonstrates a novel approach based on thermo-optic refraction, to send both beams through the sample and probe the phase deterioration due to the relative interaction of beams in the material medium. Here, thermo-optic refraction interferometry (TORI) allows the superposition of a higher order vortex beam with a non-vortex beam through the phenomenon of thermal lensing. The non-vortex beam is made to expand in a controlled fashion by another laser. The relative interaction of the expanding non-vortex beam and the vortex beam within the sample, results in the output interferogram. The phase deterioration analysis of the output interferogram elucidate medium driven phase changes. This technique is demonstrated using the milk samples by recording the RMS azimuthal phase deterioration of the OAM beam.

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“…39,40 In addition, nonlinear refractive optical switches were constructed by refraction and reflection mechanisms at the interface. 41,42 Taking Aldoped ZnO material (AZO) as an example, Al will act as a donor impurity to inject electrons and ionized donors into the bandgap of ZnO, which is attributed to Zn ions in the ZnO lattice being replaced by Al atoms. 43,44 Therefore, the donor doping effect of Al will lead to enhanced carrier mobility and excited state absorption cross-section, thereby optimizing the nonlinear absorption performance of ZnO in the field of nonlinear optics.…”

Section: Introductionmentioning

confidence: 99%