المؤلفون: Nayak, Banoj Kumar¹ (AUTHOR), Buks, Eyal¹ (AUTHOR) eyal@technion.ac.il

المصدر: Journal of Applied Physics. 11/21/2022, Vol. 132 Issue 19, p1-6. 6p.

مصطلحات موضوعية: *YTTRIUM iron garnet, *OPTICAL modulators, *INTERMODULATION, *RESONATORS, *TELECOMMUNICATION

مستخلص: We study magneto-optical coupling in a ferrimagnetic sphere resonator made of yttrium iron garnet. We find that the resonator can be operated in the telecom band as a polarization-selective optical modulator. The input state of polarization (SOP) contributing to the Stokes sideband is orthogonal to the one contributing to the anti-Stokes sideband. In the region of single sideband modulation, the SOP of both sidebands is nearly orthogonal to the SOP of the incident light. Intermodulation gain can be employed in the nonlinear regime for amplification. [ABSTRACT FROM AUTHOR]

المؤلفون: Miao, Yujie¹ (AUTHOR), Shi, Qinan¹ (AUTHOR), Zhu, Xingyu¹ (AUTHOR), Zhang, Lin¹ (AUTHOR), He, Hongsen^1,2 (AUTHOR), Dong, Jun^1,2 (AUTHOR) jdong@xmu.edu.cn

المصدر: Annalen der Physik. Mar2024, Vol. 536 Issue 3, p1-9. 9p.

مصطلحات موضوعية: *RAMAN lasers, *OPTICAL modulators, *OPTICAL vortices, *OPTICAL elements, *SPATIAL light modulators, *OPTICAL communications, *MICROSCOPY, *QUANTUM information science

مستخلص: Hybridly polarized (HP) vector vortex Raman lasers dramatically extend their applications on optical microscopy, optical communication, and quantum information. Spatial light modulators and waveplates are widely used for generating HP vector vortex lasers, however, the performance and beam quality of HP vector vortex lasers are restricted by diffraction loss and low damage threshold of these optical elements. Here, HP vector vortex Raman microchip lasers constructed with Yb3+:Y3Al5O12 (Yb:YAG) and vanadate (YVO4) crystals is demonstrated. The states of polarization (SoP) of HP vector vortex lasers are combination of radial and anti‐radial polarizations (RP‐ARP), azimuthal and anti‐azimuthal polarizations (AP‐AAP). The SoP of HP vector vortex lasers can be controlled by adjusting the length of YVO4 crystal and applying pump power. Maximum output powers are 456 and 586 mW with optical efficiency of 7.1% and 9.2% for HP vector vortex lasers with SoP of RP‐ARP and AP‐AAP. The HP vector vortex Raman lasers with SoP of RP‐ARP and AP‐AAP oscillate ≈1076 nm with bandwidths of 11.4 and 10.8 nm. High beam quality is achieved for HP vector vortex lasers with measured M2 nearly equal to theoretical value. The broadband HP vector vortex Raman lasers with high beam quality extend applications on optical trapping, and quantum information processing. [ABSTRACT FROM AUTHOR]

المؤلفون: Nezamdoost, Hamid¹ (AUTHOR), Nikoufard, Mahmoud² (AUTHOR) mnik@kashanu.ac.ir, Saghaei, Hamed^3,4 (AUTHOR)

المصدر: Optical & Quantum Electronics. Mar2024, Vol. 56 Issue 3, p1-19. 19p.

مصطلحات موضوعية: *OPTICAL modulators, *PLASMONICS, *OPTICAL modulation, *LIGHT absorption, *OPTICAL communications, *QUANTUM computing

مستخلص: This paper presents a novel design of an optical electro-absorption modulator based on a hybrid plasmonic structure with a graphene layer on the generic InP platform. Graphene-based optical modulators have the potential to revolutionize the field of optical communications. They enable high-speed data transfer and facilitate advancements in quantum computing. Developing a highly compact modulator on the InP platform represents a significant objective for photonics researchers aiming to achieve large-scale photonic integration technology. In the proposed design, a metal layer on top of a ridge waveguide creates a hybrid plasmonic structure. At the same time, light modulation is accomplished by applying a bias voltage to the graphene layer. By manipulating the optical absorption properties through changes in the Fermi level of the graphene layer, calculations demonstrate a 3 dB bandwidth exceeding 70 GHz at λ = 1.55 μm for a 1 µm length. Furthermore, the impact of metal and SiO2 dielectric layer thicknesses and chemical potential on the real part of the effective index, optical absorption, 3 dB bandwidth, extinction ratio, and insertion loss are quantitatively determined. [ABSTRACT FROM AUTHOR]

المؤلفون: Wang, Yuzhong¹ (AUTHOR), Yu, Axiang¹ (AUTHOR), Cheng, Yayun¹ (AUTHOR) chengyy@hit.edu.cn, Qi, Jiaran¹ (AUTHOR) qi.jiaran@hit.edu.cn

المصدر: Laser & Photonics Reviews. Feb2024, Vol. 18 Issue 2, p1-11. 11p.

مصطلحات موضوعية: *ARTIFICIAL neural networks, *OPTICAL modulators, *OPTICAL polarization, *ELECTROMAGNETIC fields

مستخلص: The all‐optical diffractive deep neural networks (D2NNs) framework as a hardware platform is demonstrated to implement various advanced functional meta‐devices with high parallelism and high processing speed. However, the design methodology merging trainable polarization modulation neurons into the D2NNs, which potentially possess higher integration and more task‐loading capacity, is not yet fully explored. Here, the matrix diffractive deep neural networks (M‐D2NNs) are proposed to deploy polarization‐sensitive Jones matrix metasurfaces into the all‐optical polarization multiplexing networks to perform sophisticated inference tasks as well as inverse designs for advanced functional meta‐devices. Three polarization multiplexing meta‐devices with advanced functionalities are implemented by the M‐D2NNs, that is, high task‐capacity integration classification, non‐interleaved high‐efficiency Jones matrix eight‐channel regulation, and custom‐polarization information cryptographic multiplexing. The M‐D2NNs are demonstrated to provide a new strategy to merge polarization into electromagnetic and optical field modulators by Jones matrix metasurfaces, which may drive the evolution of all‐optical networks toward multi‐task integration and more advanced functional devices. [ABSTRACT FROM AUTHOR]

المؤلفون: Xuan, Guibin¹ (AUTHOR), Gu, LiangLiang^1,2,3 (AUTHOR) llgu@usst.edu.cn, Peng, Runling¹ (AUTHOR), Hu, Haifeng^1,2,3 (AUTHOR)

المصدر: Plasmonics. Feb2024, Vol. 19 Issue 1, p159-165. 7p.

مصطلحات موضوعية: *OPTICAL properties, *OPTICAL modulators, *SPECTRAL sensitivity, *CIRCULAR polarizers, *CURRENT fluctuations, *DICHROISM, *CIRCULAR dichroism

مستخلص: Nanostructures with chiral features have a wide range of applications in circular polarizers, optical modulators, and optoelectronic devices. In this study, we designed a three-dimensional bilayer T-shaped chiral structure to investigate the circular dichroism of multilayer nanostructures. We simulated the designed chiral structure and results that showed the maximum circular dichroism value occurred when the lower layer T-shaped structure rotated to 40°. The spectral response of the proposed structure can be considered as a coupling between upper and lower resonances, and the mechanism of optical chirality is explored by simulating the internal current distribution in metal. The model revealed that different current oscillations were excited by incident light in the upper and lower layers. Our results provide insightful references for analyzing the physical mechanism of circular dichroism signals and improving the circular dichroism signals of metasurfaces. [ABSTRACT FROM AUTHOR]

المؤلفون: Wang, Jianlei¹ (AUTHOR), Cai, Lingbo¹ (AUTHOR), Xie, Liangyue¹ (AUTHOR), Liu, Jun² (AUTHOR), Zhong, Zijun² (AUTHOR), Liu, Zhi³ (AUTHOR), Han, Jing^4,5 (AUTHOR), Meng, Xianfeng¹ (AUTHOR), Xiao, Quanlan² (AUTHOR) xiaoql@szu.edu.cn, Wang, Chun¹ (AUTHOR) chunwang@sdu.edu.cn

المصدر: Journal of Modern Optics. Mar2023, Vol. 70 Issue 5, p322-326. 5p.

مصطلحات موضوعية: Q-switched lasers, OPTICAL modulators, LASERS, INDIUM selenide, LASER pulses

مستخلص: We report on a compact 808 nm diode-pumped passively Q-switched (PQS) Nd:YVO4 laser at 1064 nm with black phosphorus (BP)/ indium selenide (InSe) heterostructure as a saturable absorber (SA). When the transmission of the output coupler (OC) was 30%, the maximum continuous-wave (CW) output power of 10.3 W was obtained with a slope efficiency of 52.4% under the incident pump power of 22 W. The maximum average output power of 3.1 W was obtained at 9.29 W pump power, corresponding to the repetition rate of 598 kHz and the pulse width of 455 ns during pulse operation, further power scaling was limited by the damage threshold of the saturable absorber mirror (SAM). The results sufficiently validated that two-dimensional (2D) BP/InSe heterostructure could be used as an optical modulator for near-IR pulsed laser sources. [ABSTRACT FROM AUTHOR]

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المؤلفون: Parfenov, Mikhail¹ (AUTHOR) mvparfenov@mail.ioffe.ru, Agruzov, Petr¹ (AUTHOR), Tronev, Aleksandr¹ (AUTHOR), Ilichev, Igor¹ (AUTHOR), Usikova, Anna¹ (AUTHOR), Zadiranov, Yurii¹ (AUTHOR), Shamrai, Aleksandr¹ (AUTHOR) mvparfenov@mail.ioffe.ru

المصدر: Nanomaterials (2079-4991). Oct2023, Vol. 13 Issue 20, p2755. 12p.

مصطلحات موضوعية: *MULTIMODE waveguides, *OPTICAL modulators, *LIGHT propagation, *ELECTRODES, *LITHIUM niobate, *METALS, *WAVEGUIDES, *ELECTRO-optical effects

مستخلص: An approach for filtering the fundamental mode in an integrated optical modulator with multimode waveguides based on etched thin lithium niobate nanofilms is presented. It is shown that metal electrodes can be used as a modal filter to suppress high-order modes in wide multimode ridge waveguides and, consequently, to provide their quasi-single-mode regime of operation. The influence of the gap between the electrodes and its displacement relative to the waveguide symmetry axis is analyzed for various configurations of waveguides. The conditions for quasi-single-mode light propagation with suppression of high-order modes of more than 90 dB/cm are found. The influence of fabrication errors on the efficiency of modal filtering is discussed. Efficient electro-optical modulation with an equivalent voltage-length product of 4 V∙cm has been experimentally demonstrated on integrated optical phase modulator samples fabricated using conventional contact photolithography. The proposed topological solution can be further used for the fast and cheap fabrication of TFLN modulators by conventional contact photolithography. The proposed modal filtering can also be used in other waveguide topologies and in more complex waveguide devices. [ABSTRACT FROM AUTHOR]

المؤلفون: Younis, B. M.^1,2 (AUTHOR), Dawood, Nada Yazeed M.^1,2 (AUTHOR), Mahmoud, Saleh¹ (AUTHOR), El-Sayed, Bilal¹ (AUTHOR), Usama, El-Sayed¹ (AUTHOR), Almoqadem, Mohamed H.¹ (AUTHOR), Hameed, Mohamed Farhat O.^2,3,4 (AUTHOR) mfarahat@zewailcity.edu.eg, Obayya, S. S. A.^2,5 (AUTHOR) sobayya@zewailcity.edu.eg

المصدر: Optical & Quantum Electronics. Sep2023, Vol. 55 Issue 9, p1-15. 15p.

مصطلحات موضوعية: *PHASE change materials, *OPTICAL modulators, *PHOTONIC crystal fibers, *LIGHT propagation, *PHASE transitions, *FINITE element method, *FINITE differences

مستخلص: Photonic crystal fibers (PCFs) have recently attracted compelling attention because of their numerous applications, particularly in the mid-infrared (mid-IR) wavelength region. In this paper, we have presented and analyzed mid-IR optical modulator based on phase-changing material (PCM) known as germanium-antimony-tellurium (GST) and D-shaped PCF. The modulation process can be performed as the GST material's phase undergoes a transition between amorphous (on) and crystalline (off) states. To analyze the proposed design numerically, full vectorial finite element method (FVFEM) is employed. Further, we studied the light propagation through the suggested structure using 3D finite difference time domain (FDTD) method. The optical losses of the fundamental transverse electric (TE) mode supported by the reported structure in the two GST states are studied. The obtained extinction ratio (ER) of the proposed modulator approaches 302.61 dB, whereas the insertion loss (IL) is less than 0.00014 dB throughout the wavelength range from 3 to 5.8 μm at a device length (LD) of 0.2 mm. Therefore, the suggested modulator can be utilized in photonic integrated circuits that require high ER, very low IL, and large optical bandwidth. [ABSTRACT FROM AUTHOR]

المؤلفون: Kulachenkov, Nikita K.¹ (AUTHOR), Orlioglo, Bogdan² (AUTHOR), Vasilyev, Eugene S.³ (AUTHOR), Povarov, Svyatoslav A.¹ (AUTHOR), Agafontsev, Alexander M.^3,4 (AUTHOR), Bachinin, Semyon¹ (AUTHOR), Shipilovskikh, Sergei¹ (AUTHOR), Lunev, Artem¹ (AUTHOR), Samsonenko, Denis G.⁵ (AUTHOR), Fedin, Vladimir P.⁵ (AUTHOR), Kovalenko, Konstantin A.⁵ (AUTHOR) k.a.kovalenko@niic.nsc.ru, Milichko, Valentin A.^1,6 (AUTHOR) valentin.milichko@univ-lorraine.fr

المصدر: Chemical Communications. 8/25/2023, Vol. 59 Issue 66, p9964-9967. 4p.

مصطلحات موضوعية: *OPTICAL modulators, *OPTICAL modulation, *ORGANIC bases

مستخلص: We report on the design of 1D MOFs based on a nopinane-annelated organic ligand and Co(II) or Ni(II), the variation of which allows tuning the optical modulation bandwidth. Structural and time-resolved analysis revealed the optical modulation mechanism, the rates and its endurance, thereby enriching the list of sustainable MOFs for tunable optical modulators. [ABSTRACT FROM AUTHOR]

المؤلفون: Sinatkas, Georgios¹ (AUTHOR), Christopoulos, Thomas¹ (AUTHOR), Tsilipakos, Odysseas² (AUTHOR), Kriezis, Emmanouil E.¹ (AUTHOR) mkriezis@auth.gr

المصدر: Journal of Applied Physics. 7/7/2021, Vol. 130 Issue 1, p1-35. 35p.

مصطلحات موضوعية: *OPTICAL modulators, *OPTICAL modulation, *TELECOMMUNICATION systems, *PHOTONICS, *PHENOMENOLOGICAL theory (Physics), *INSERTION loss (Telecommunication)

مستخلص: Electro-optic modulators are an indispensable part of photonic communication systems, largely dictating the achievable transmission rate. Recent advances in materials and fabrication/processing techniques have brought new elements and a renewed dynamic to research on optical modulation. Motivated by the new opportunities, this Perspective reviews the state of the art in integrated electro-optic modulators, covering a broad range of contemporary materials and integrated platforms. To provide a better overview of the status of current modulators, an assessment of the different material platforms is conducted on the basis of common performance metrics: extinction ratio, insertion loss, electro-optic bandwidth, driving voltage, and footprint. The main physical phenomena exploited for electro-optic modulation are first introduced, aiming to provide a self-contained reference to researchers in physics and engineering. Additionally, we take care to highlight topics that can be overlooked and require attention, such as the accurate calculation of carrier density distribution and energy consumption, the correct modeling of thin and two-dimensional materials, and the nature of contact electrodes. Finally, a future outlook for the different electro-optic materials is provided, anticipating the research and performance trends in the years to come. [ABSTRACT FROM AUTHOR]