| 1. |
- A Atlasov, Kirill, et al.
(author)
-
1D photonic band formation and photon localization in finite-size photonic-crystal waveguides
- 2010
-
In: OPTICS EXPRESS. - 1094-4087. ; 18:1, s. 117-122
-
Journal article (peer-reviewed)abstract
- A transition from discrete optical modes to 1D photonic bands is experimentally observed and numerically studied in planar photonic-crystal (PhC) L-N microcavities of length N. For increasing N the confined modes progressively acquire a well-defined momentum, eventually reconstructing the band dispersion of the corresponding waveguide. Furthermore, photon localization due to disorder is observed experimentally in the membrane PhCs using spatially resolved photoluminescence spectroscopy. Implications on single-photon sources and transfer lines based on quasi-1D PhC structures are discussed.
|
|
| 2. |
- Alarcon, Alvaro, et al.
(author)
-
Dynamic generation of photonic spatial quantum states with an all-fiber platform
- 2023
-
In: Optics Express. - : Optica Publishing Group. - 1094-4087. ; 31:6, s. 10673-10683
-
Journal article (peer-reviewed)abstract
- Photonic spatial quantum states are a subject of great interest for applications in quantum communication. One important challenge has been how to dynamically generate these states using only fiber-optical components. Here we propose and experimentally demonstrate an all-fiber system that can dynamically switch between any general transverse spatial qubit state based on linearly polarized modes. Our platform is based on a fast optical switch based on a Sagnac interferometer combined with a photonic lantern and few-mode optical fibers. We show switching times between spatial modes on the order of 5 ns and demonstrate the applicability of our scheme for quantum technologies by demonstrating a measurement-device-independent (MDI) quantum random number generator based on our platform. We run the generator continuously over 15 hours, acquiring over 13.46 Gbits of random numbers, of which we ensure that at least 60.52% are private, following the MDI protocol. Our results show the use of photonic lanterns to dynamically create spatial modes using only fiber components, which due to their robustness and integration capabilities, have important consequences for photonic classical and quantum information processing.(c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement
|
|
| 3. |
- Alarcon, Alvaro, 1991-, et al.
(author)
-
Polarization-independent single-photon switch based on a fiber-optical Sagnac interferometer for quantum communication networks
- 2020
-
In: Optics Express. - : OPTICAL SOC AMER. - 1094-4087. ; 28:22, s. 33731-33738
-
Journal article (peer-reviewed)abstract
- An essential component of future quantum networks is an optical switch capable of dynamically routing single photons. Here we implement such a switch, based on a fiber-optical Sagnac interferometer design. The routing is implemented with a pair of fast electro-optical telecom phase modulators placed inside the Sagnac loop, such that each modulator acts on an orthogonal polarization component of the single photons, in order to yield polarization-independent capability that is crucial for several applications. We obtain an average extinction ratio of more than 19 dB between both outputs of the switch. Our experiment is built exclusively with commercial off-the-shelf components, thus allowing direct compatibility with current optical communication systems. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
|
|
| 4. |
- Arwin, Hans, et al.
(author)
-
Cuticle structure of the scarab beetle Cetonia aurata analyzed by regression analysis of Mueller-matrix ellipsometric data
- 2013
-
In: Optics Express. - : Optical Society of America. - 1094-4087. ; 21:19, s. 22645-22656
-
Journal article (peer-reviewed)abstract
- Since one hundred years it is known that some scarab beetles reflect elliptically and near-circular polarized light as demonstrated by Michelson for the beetle Chrysina resplendens. The handedness of the polarization is in a majority of cases left-handed but also right-handed polarization has been found. In addition, brilliant colors with metallic shine are observed. The polarization and color effects are generated in the beetle exoskeleton, the so-called cuticle. The objective of this work is to demonstrate that structural parameters and materials optical functions of these photonic structures can be extracted by advanced modeling of spectral multi-angle Mueller-matrix data recorded from beetle cuticles. A dual-rotating compensator ellipsometer is used to record normalized Mueller-matrix data in the spectral range 400 – 800 nm at angles of incidence in the range 25–75°. Analysis of data measured on the scarab beetle Cetonia aurata are presented in detail. The model used in the analysis mimics a chiral nanostructure and is based on a twisted layered structure. Given the complexity of the nanostructure, an excellent fit between experimental and model data is achieved. The obtained model parameters are the spectral variation of the refractive indices of the cuticle layers and structural parameters of the chiral structure.
|
|
| 5. |
- Arwin, Hans, et al.
(author)
-
Sum decomposition of Mueller-matrix images and spectra of beetle cuticles
- 2015
-
In: Optics Express. - : Optical Society of America. - 1094-4087. ; 23:3, s. 1951-1966
-
Journal article (peer-reviewed)abstract
- Spectral Mueller matrices measured at multiple angles of incidence as well as Mueller matrix images are recorded on the exoskeletons (cuticles) of the scarab beetles Cetonia aurata and Chrysina argenteola. Cetonia aurata is green whereas Chrysina argenteola is gold-colored. When illuminated with natural (unpolarized) light, both species reflect left-handed and near-circularly polarized light originating from helicoidal structures in their cuticles. These structures are referred to as circular Bragg reflectors. For both species the Mueller matrices are found to be nondiagonal depolarizers. The matrices are Cloude decomposed to a sum of non-depolarizing matrices and it is found that the cuticle optical response, in a first approximation can be described as a sum of Mueller matrices from an ideal mirror and an ideal circular polarizer with relative weights determined by the eigenvalues of the covariance matrices of the measured Mueller matrices. The spectral and image decompositions are consistent with each other. A regression-based decomposition of the spectral and image Mueller matrices is also presented whereby the basic optical components are assumed to be a mirror and a circular polarizer as suggested by the Cloude decomposition. The advantage with a regression decomposition compared to a Cloude decomposition is its better stability as the matrices in the decomposition are determined a priori. The origin of the depolarizing features are discussed but from present data it is not possible to conclude whether the two major components, the mirror and the circular polarizer are laterally separated in domains in the cuticle or if the depolarization originates from the intrinsic properties of the helicoidal structure.
|
|
| 6. |
- Atlasov, K.A., et al.
(author)
-
Wavelength and loss splitting in directly coupled photonic-crystal defect microcavities
- 2008
-
In: Optics Express. - 1094-4087. ; 16:20, s. 16255-16264
-
Journal article (peer-reviewed)abstract
- Coupling between photonic-crystal defect microcavities is observed to result in a splitting not only of the mode wavelength but also of the modal loss. It is discussed that the characteristics of the loss splitting may have an important impact on the optical energy transfer between the coupled resonators. The loss splitting - given by the imaginary part of the coupling strength - is found to arise from the difference in diffractive outof-plane radiation losses of the symmetric and the antisymmetric modes of the coupled system. An approach to control the splitting via coupling barrier engineering is presented. © 2008 Optical Society of America.
|
|
| 7. |
- Atlasow, Kirill A., et al.
(author)
-
Photonic-crystal microcavity laser with site-controlled quantum-wire active medium
- 2009
-
In: Optics Express. - 1094-4087. ; 17:20, s. 18178-18183
-
Journal article (peer-reviewed)abstract
- Site-controlled quantum-wire photonic-crystal microcavity laser is experimentally demonstrated using optical pumping. The single-mode lasing and threshold are established based on the transient laser response, linewidth narrowing, and the details of the non-linear power input-output charateristics. Average-power threshold as low as ~240 nW (absorbed power) and spontaneous emission coupling coefficient β~0.3 are derived.
|
|
| 8. |
- Belonovski, Alexey V, et al.
(author)
-
Quantum analysis of luminescence of an exciton in a meso-cavity
- 2021
-
In: Optics Express. - : Optical Society of America. - 1094-4087. ; 29:13, s. 20724-20734
-
Journal article (peer-reviewed)abstract
- Interaction of cavity modes with an exciton in a meso-cavity (the structure supporting several cavity modes separated by an energy interval comparable to Rabi-splitting of an exciton and cavity modes) has been analyzed using a quantum-mechanical approach. Simultaneous interaction of an exciton and several cavity modes results in few novel effects such as ladder-like increase of the exciton population in the system, quantum beating and non-monotonic dependence of the ground polariton state in the system on the pumping. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.
|
|
| 9. |
- Belonovski, Alexey V, et al.
(author)
-
Weak and strong coupling of photons and excitons in planar meso-cavities
- 2020
-
In: Optics Express. - : OPTICAL SOC AMER. - 1094-4087. ; 28:9, s. 12688-12698
-
Journal article (peer-reviewed)abstract
- The interaction of an exciton and cavity modes is considered in planar meso-cavities, which have lateral sizes corresponding to few wavelengths. In meso-cavities, the frequency interval between the optical modes is comparable or smaller than the value of the Rabi splitting between the exciton and the optical modes. The Hamiltonian of the interaction between the exciton and the cavity modes is constructed, and it is shown that such an interaction between the cavity modes and the exciton can occur both in weak and in strong coupling regimes. The latter case can be accompanied by a pronounced splitting of the emission peaks as shown for modelled meso-cavities of triangular, square and hexagonal shapes, where it is demonstrated that Q-factors for the adjacent cavity modes as well as the strength of interaction with excitons can differ by few orders of magnitude. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
|
|
| 10. |
- Berzins, Andris, et al.
(author)
-
NV microscopy of thermally controlled stresses caused by thin Cr2O3 films
- 2023
-
In: Optics Express. - : Optica Publishing Group. - 1094-4087. ; 31:11, s. 17950-17963
-
Journal article (peer-reviewed)abstract
- Many modern applications, including quantum computing and quantum sensing, use substrate-film interfaces. Particularly, thin films of chromium or titanium and their oxides are commonly used to bind various structures, such as resonators, masks, or microwave antennas, to a diamond surface. Due to different thermal expansions of involved materials, such films and structures could produce significant stresses, which need to be measured or predicted. In this paper, we demonstrate imaging of stresses in the top layer of diamond with deposited structures of Cr2O3 at temperatures 19 & DEG;C and 37 & DEG;C by using stress-sensitive optically detected magnetic resonances (ODMR) in NV centers. We also calculated stresses in the diamond-film interface by using finite-element analysis and correlated them to measured ODMR frequency shifts. As predicted by the simulation, the measured high-contrast frequency-shift patterns are only due to thermal stresses, whose spin-stress coupling constant along the NV axis is 21 & PLUSMN;1 MHz/GPa, that is in agreement with constants previously obtained from single NV centers in diamond cantilever. We demonstrate that NV microscopy is a convenient platform for optically detecting and quantifying spatial distributions of stresses in diamond-based photonic devices with micrometer precision and propose thin films as a means for local application of temperature-controlled stresses. Our results also show that thin-film structures produce significant stresses in diamond substrates, which should be accounted for in NV-based applications.
|
|
