Optics

10 pages, 3150 KiB

Open AccessArticle

A Multi-Spectral Thermal Gas Detection Imager Using Uncooled Infrared Camera

by Fang-Xiao Cui, Yue Zhao, An-Jing Wang, Feng-Xiang Ma, Jun Wu, Yang-Yu Li, Da-Cheng Li and Wang-Chao Dong

Optics 2022, 3(4), 473-482; https://doi.org/10.3390/opt3040040 - 12 Dec 2022

Cited by 4 | Viewed by 2543

Abstract

Gas remote detection is useful for early warning of gas leakage and toxic chemicals. Optical gas imaging (OGI) built with an uncooled infrared camera is superior to cooled detectors in terms of cost. Current mainstream OGI technologies fall short in their detection of [...] Read more.

Gas remote detection is useful for early warning of gas leakage and toxic chemicals. Optical gas imaging (OGI) built with an uncooled infrared camera is superior to cooled detectors in terms of cost. Current mainstream OGI technologies fall short in their detection of gases at ambient temperature and their ability to classify multiple gases. A multi-spectral uncooled imager is developed to try to solve these problems, which is constructed from a commercial uncooled thermal camera and wide band filters. To solve filter self-radiation and unevenness, a correction method is devised, with an ambient temperature blackbody placed in front and subtracted from the measured image. Based on waveband cutoffs, filters are classified into target-sensitive filters and background filters. Multi-spectra are simulated according to wide band filter transmittance, which can be used in gas classification. A sulfur hexafluoride (SF6) experiment is conducted outdoors at a distance of 10 m. An SVM model is trained to classify gas release in real time. Detection with a cold sky background is improved with the aid of data cube differences in a time sequence. The SF6 outdoor experiment concluded with preliminary effective results of ambient temperature gas remote detection. Full article

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11 pages, 2289 KiB

Open AccessArticle

Topological and Optical Properties of Passeriformes’ Feathers: Biological UV Reflector Antenna

by P. Singh, M. A. Jalil, P. Yupapin, J. Ali, M. A. Palomino, M. Toledo-Solano, K. Misaghian, J. Faubert, K. Ray, A. Bandyopadhyay and J. E. Lugo

Optics 2022, 3(4), 462-472; https://doi.org/10.3390/opt3040039 - 5 Dec 2022

Viewed by 1788

Abstract

This manuscript explores the topological and optical properties of a Passeriformes bird feather. Inside the feather, the layers of keratin and melanin are responsible for light reflection, transmission, and absorption; notably, the miniature composition of melanosome barbules plays a crucial role in its [...] Read more.

This manuscript explores the topological and optical properties of a Passeriformes bird feather. Inside the feather, the layers of keratin and melanin are responsible for light reflection, transmission, and absorption; notably, the miniature composition of melanosome barbules plays a crucial role in its reflective properties. We adopted a multilayer interference model to investigate light propagation throughout the Passeriformes plume. As a result, we obtained all necessary simulated results, such as resonance band, efficiency, and electromagnetic radiation patterns of the Passeriformes plume, and they were verified with the experimental results reported in the literature study regarding light reflectivity through its internal geometry. Interestingly, we discovered that the interior structure of the Passeriformes plume functions similarly to a UV reflector antenna. Full article

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15 pages, 2137 KiB

Open AccessArticle

Design of a Highly Sensitive Detector Using a Ternary Photonic Crystal (PC) Based on Titanium Nitride Sandwiched between Si and SiO₂ for the Creatinine Concentration Detection in the Blood Serum

by Malek G. Daher, Youssef Trabelsi, Abinash Panda, Ashot H. Gevorgyan, Khedr M. Abohassan, Lassaad K. Smirani, Baraa Riyadh Altahan and Ahmed Nabih Zaki Rashed

Optics 2022, 3(4), 447-461; https://doi.org/10.3390/opt3040038 - 29 Nov 2022

Cited by 12 | Viewed by 1743

Abstract

It is very important to design a rapid and sensitive device for the creatinine concentration detection due to it being one of the most considerable benchmarks for efficient kidney working. Here, a novel biophotonic sensor using one-dimensional ternary PC based on Si/TiN/SiO₂ [...] Read more.

It is very important to design a rapid and sensitive device for the creatinine concentration detection due to it being one of the most considerable benchmarks for efficient kidney working. Here, a novel biophotonic sensor using one-dimensional ternary PC based on Si/TiN/SiO₂ layers is proposed for the creatinine concentration detection in a blood serum sample. A central cavity layer is inserted between two equal periodic numbers. The blood sample can be infiltrated in the cavity layer with various creatinine concentrations. Based on the technique of transfer matrix, the transmittance spectra properties are investigated. The influences of variation of the incidence angle for both TE and TM polarizations and the cavity layer thickness are carefully investigated to attain the best sensitivity of the biophotonic detector. A high sensitivity of 938.02 nm/RIU is realized for the suggested detector, which is comparable to most recent works published in this area. Moreover, the proposed sensor has an inexpensive cost, real-time detection, and simple structure, which is helpful to the industrial design using low-cost product nanofabrication techniques. Based on above-mentioned outcomes, our biosensor candidate is a suitable and effective device for the detection of creatinine concentration, and it can use for any biological sample. Full article

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9 pages, 1580 KiB

Open AccessArticle

Ultrafast Phonon Decay in Complex Oxides

by Chandra P. Neupane, Jeremy Sylvester, Dinusha M. S. R. Mudiyanselage, Helani A. S. Singhapurage and Feruz Ganikhanov

Optics 2022, 3(4), 438-446; https://doi.org/10.3390/opt3040037 - 21 Nov 2022

Viewed by 1889

Abstract

The decay of multiple Raman active vibrations has been directly traced, in time, in technologically important wide bandgap semiconduction oxides such as BaSnO₃ (BSO), STiO₃ (STO), and KTiOPO₄ (KTP) crystal, which have important applications in laser frequency conversion. A time-domain [...] Read more.

The decay of multiple Raman active vibrations has been directly traced, in time, in technologically important wide bandgap semiconduction oxides such as BaSnO₃ (BSO), STiO₃ (STO), and KTiOPO₄ (KTP) crystal, which have important applications in laser frequency conversion. A time-domain coherent Raman technique, with excellent time (~120 fs) and spectral resolutions, has been applied to measure the ultrafast decay rates of optical phonons with 350–1500 cm⁻¹ frequencies. Phonon decay mechanisms via phonon energy loss due to second- and third-order parametric processes have been discussed. The correspondingly high equivalent spectral resolution allowed for the determination of the phonon line bandwidths to be within 7.2–8.3 cm⁻¹ (BSO), 8.5–9.7 cm⁻¹ (STO), and 6.2–18.6 cm⁻¹ (KTP). Full article

(This article belongs to the Section Nonlinear Optics)

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8 pages, 3381 KiB

Open AccessArticle

Quantum Network Intelligent Management System

by Iván García-Cobo

Optics 2022, 3(4), 430-437; https://doi.org/10.3390/opt3040036 - 15 Nov 2022

Viewed by 1749

Abstract

Quantum network materializes the paradigm change caused by the depletion of classical computation. Quantum networks have been built gathering reliable quantum repeaters connected by optical fiber networks. The need to build robust and resilient networks against hacking attacks is fundamental in the design [...] Read more.

Quantum network materializes the paradigm change caused by the depletion of classical computation. Quantum networks have been built gathering reliable quantum repeaters connected by optical fiber networks. The need to build robust and resilient networks against hacking attacks is fundamental in the design of the future quantum Internet, detecting structural security as the major issue in the current development of the technology. A network management method is proposed to achieve its real-time adaptation and to protect itself against sabotage or accidents that render part of the network or its nodes useless. Full article

(This article belongs to the Special Issue Advances in Optical Quantum Communication Technology)

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21 pages, 349 KiB

Open AccessArticle

Improving Early Optics Instruction Using a Phenomenological Approach: A Field Study

by Kai Fliegauf, Janika Sebald, Joaquin Marc Veith, Henrike Spiecker and Philipp Bitzenbauer

Optics 2022, 3(4), 409-429; https://doi.org/10.3390/opt3040035 - 9 Nov 2022

Cited by 7 | Viewed by 2847

Abstract

Previous research has shown that phenomenological approaches in early optics education might be superior to traditional model-based instruction based on the light ray realm with regards to fostering students’ conceptual understanding of basic optics topics. However, it remains open to date which learning [...] Read more.

Previous research has shown that phenomenological approaches in early optics education might be superior to traditional model-based instruction based on the light ray realm with regards to fostering students’ conceptual understanding of basic optics topics. However, it remains open to date which learning difficulties students encounter when being introduced to optics following a phenomenological approach—in particular, in comparison to the learning difficulties that are widespread among students introduced to optics via traditional model-based instruction. With this article, we contribute to closing this gap: We report the results of a quasi-experimental field study with

N = 189

secondary school students. We used ten items adapted from the literature in a pre-posttest design for an in-depth exploration of the conceptions of introductory optics topics acquired by

N = 89

students introduced to optics following a phenomenological teaching-learning sequence and compare these students’ conceptions to the ones acquired by

N = 100

peers who participated in traditional model-based instruction covering the same content topics. The results of this study substantiate earlier findings according to which phenomenological teaching might be a fruitful endeavour for early optics education, in particular, when it comes to teaching and learning about image formation by converging lenses. Full article

(This article belongs to the Special Issue Optics and Photonics: Technologies, Methods and Facilities in the 21st Century Teaching)

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9 pages, 2531 KiB

Open AccessArticle

Sagnac Interferometric Temperature Sensor Based on Boron-Doped Polarization-Maintaining Photonic Crystal Fibers

by Lan Cheng, Jun Liang, Shiwei Xie and Yilin Tong

Optics 2022, 3(4), 400-408; https://doi.org/10.3390/opt3040034 - 5 Nov 2022

Cited by 2 | Viewed by 1484

Abstract

A sensitive temperature sensor was demonstrated using boron-doped polarization-maintaining photonic crystal fiber (PM-PCF) as a Sagnac interferometer (SI). This boron-doped PM-PCF combines both the geometric birefringence introduced by the PCF structure design and the stress birefringence introduced by the boron-doped stress-applying parts. However, [...] Read more.

A sensitive temperature sensor was demonstrated using boron-doped polarization-maintaining photonic crystal fiber (PM-PCF) as a Sagnac interferometer (SI). This boron-doped PM-PCF combines both the geometric birefringence introduced by the PCF structure design and the stress birefringence introduced by the boron-doped stress-applying parts. However, we found that the stress birefringence dominates the total birefringence of the sensor by numerical analysis. In the experiments, the fabricated sensor exhibited the highest temperature sensitivity of −1.83 nm/°C within the wide temperature range of 28~76 °C. The temperature sensitivity was mainly derived from the stress birefringence of boron-doped PM-PCF SI. These findings provide some support for the designation of high-precision temperature sensors. Full article

(This article belongs to the Topic Advances in Optical Sensors)

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16 pages, 3408 KiB

Open AccessArticle

Understanding the Real Effect of the High-Order Aberrations after Myopic Femto-Lasik

by Juan J. Miret, Ester Rojas, Vicente J. Camps, Celia Garcia, Maria T. Caballero, Begoña Martín and Enrique Chipont

Optics 2022, 3(4), 384-399; https://doi.org/10.3390/opt3040033 - 9 Oct 2022

Cited by 1 | Viewed by 3523

Abstract

In this work we try to understand the real effect of increase in aberrations after Femto-LASIK surgery on the patient’s final visual quality, specifically when the visual acuity measurement is considered. A clinical study with 37 eyes of 20 patients that underwent myopic [...] Read more.

In this work we try to understand the real effect of increase in aberrations after Femto-LASIK surgery on the patient’s final visual quality, specifically when the visual acuity measurement is considered. A clinical study with 37 eyes of 20 patients that underwent myopic Femto-LASIK surgery and different personalized eye model simulations were carried out. In clinical study, correlations between pre- and postoperative parameters with visual acuity were analysed. Eye simulations (based on real data) provided simulations of vision quality before and after surgery. Our main results showed a significant increase in aberrations was obtained after surgery; however, no differences were found between the preoperative corrected distance visual acuity (CDVA) and the postoperative uncorrected distance visual acuity (UDVA). This absence of differences in visual quality could be explained by performing different simulations on three eyes that would cover most of the possible clinical situations. Simulations were implemented considering a pupil size of 2.5 mm and the personalized data of each patient. Results showed that final visual acuity (VA) change are determined by the final high-order aberrations (HOAS) and their increase after surgery but measured under photopic conditions. In conclusion, customized analysis of higher-order aberrations in scotopic pupils better predicts patient visual acuity after Lasik surgery. Full article

(This article belongs to the Special Issue Advances in Vision Optics, Myopia Control and Refractive Surgery)

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20 pages, 1001 KiB

Open AccessArticle

Temporal Solitons in an Optically Injected Kerr Cavity with Two Spectral Filters

by Alexander Pimenov and Andrei G. Vladimirov

Optics 2022, 3(4), 364-383; https://doi.org/10.3390/opt3040032 - 23 Sep 2022

Cited by 1 | Viewed by 1817

Abstract

We propose and analyze a theoretical scheme of an injected Kerr cavity, where the chromatic dispersion is induced by propagation of light through two Lorentzian spectral filters with different widths and central frequencies. We show that this setup can be modeled by a [...] Read more.

We propose and analyze a theoretical scheme of an injected Kerr cavity, where the chromatic dispersion is induced by propagation of light through two Lorentzian spectral filters with different widths and central frequencies. We show that this setup can be modeled by a second order delay differential equation that can be considered as a generalization of the Ikeda map with included spectral filtering, dispersion, and coherent injection terms. We demonstrate that this equation can exhibit modulational instability and bright localized structures formation in the anomalous dispersion regime. Full article

(This article belongs to the Section Nonlinear Optics)

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12 pages, 2709 KiB

Open AccessArticle

Contour Measurement of Object with Arbitrary Surface Using Two-Dimensional Shearography with Source Displacement

by Miao Yu, Sijin Wu, Weixian Li and Juanning Si

Optics 2022, 3(4), 352-363; https://doi.org/10.3390/opt3040031 - 22 Sep 2022

Cited by 1 | Viewed by 1714

Abstract

A two-dimensional (2D) shearography with source displacement is proposed to measure object contours. Using a dual-shear shearographic setup with two movable laser sources, the full-field slopes along a pair of orthogonal shear directions were obtained. The contour was then obtained by performing 2D [...] Read more.

A two-dimensional (2D) shearography with source displacement is proposed to measure object contours. Using a dual-shear shearographic setup with two movable laser sources, the full-field slopes along a pair of orthogonal shear directions were obtained. The contour was then obtained by performing 2D integration of the surface slopes. Theoretical derivations and experimental results are presented to demonstrate the performance of the proposed method. The experimental results show that contour of objects with various types of surfaces, such as spherical and hyperbolic paraboloid surfaces, can be effectively measured. The measurement of the contour aids in the precision measurement of strain and the precision location of defects. Full article

(This article belongs to the Section Engineering Optics)

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14 pages, 317 KiB

Open AccessReview

The Rationale for the Optimal Continuous-Variable Quantum Key Distribution Protocol

by Roman Goncharov, Irina Vorontsova, Daniil Kirichenko, Ilya Filipov, Iurii Adam, Vladimir Chistiakov, Semyon Smirnov, Boris Nasedkin, Boris Pervushin, Daria Kargina, Eduard Samsonov and Vladimir Egorov

Optics 2022, 3(4), 338-351; https://doi.org/10.3390/opt3040030 - 21 Sep 2022

Cited by 4 | Viewed by 2316

Abstract

This article describes the current technical level of developments in the field of continuous-variable quantum key distribution (CV-QKD). Various classifications are described, the criteria are analyzed, and the optimal protocol is selected. The analysis is focused around device-dependent schemes with a theoretical emphasis, [...] Read more.

This article describes the current technical level of developments in the field of continuous-variable quantum key distribution (CV-QKD). Various classifications are described, the criteria are analyzed, and the optimal protocol is selected. The analysis is focused around device-dependent schemes with a theoretical emphasis, and therefore, a detailed analysis of device-independent CV-QKD and side-channel attacks is out of the scope of the work. However, the latter, one way or another, is taken into account when describing possible classifications. The choice of the optimal protocol was carried out, first of all, from the potential possibility of integration into existing network telecommunication infrastructures. Predominantly, the general classification is carried out in such a way that it is possible to draw up a specific protocol, depending on the task of implementation. Full article

(This article belongs to the Special Issue Advances in Optical Quantum Communication Technology)

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Optics, Volume 3, Issue 4 (December 2022) – 11 articles

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