Optics Commons^™

Modelling The Formation Of Unslanted Holographic Gratings In Hybrid Photopolymer Media, Jack Lyons, Dana Mackey, Izabela Naydenova

Articles

The theoretical modelling of holographic recording in photopolymers has been an important tool in their optimisation. More complex, hybrid organic/inorganic photopolymers have been developed in pursuit of materials with higher sensitivity, low shrinkage, high dynamic range and environmental stability. Recent attempts to augment the existing models for the redistribution of inorganic nanoparticles in holographic recording were successful but there is still a knowledge gap in regards to modelling optical losses, mutual cross-diffusion, the formation of slanted holographic gratings and polymerization induced shrinkage in hybrid photopolymer media. This paper will describe a novel approach to modelling the formation of unslanted holographic …

Comparing Thin And Volume Regimes Of Analog Holograms For Wavefront Sensing, Emma Branigan, Andreas Zepp, Suzanne Martin, Matthew Sheehan, Szymon Gladysz, Kevin Murphy

Articles

Two analog holographic wavefront sensors, for measurement of defocus, have been fabricated as both thin and volume phase transmission holograms in a self-developing photopolymer. This represents the first reported direct comparison of hologram regimes when designed for wavefront sensing. An analysis of the effect of crosstalk in the presence of one other aberration mode (astigmatism X (0/90°), coma X (horizontal), and primary spherical aberration) was carried out with each version of the sensor. The performance of thin and volume analog holographic wavefront sensors was characterized under emulated conditions associated with moderate atmospheric turbulence.

Investigation Of The Uv-Resistance Of Photopolymerisable Glass For Space Applications, Luca Sorridente, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy

Articles

The progress of space based scientific research leads to an increasing demand for more efficient and less bulky instruments. Conventional refractive elements make up a critical part of many optical instruments launched into space; however, they can be bulky and heavy. Holographic optical elements are an efficient alternative to replace the conventional optical elements as they are lightweight and can be miniaturized. Current materials typically used for volume holographic optical elements are not robust enough for use in space environment. Recently a promising photopolymerisable glass has been developed using a sol-gel technique, which can provide dry layers suitable for holographic …

Photopolymer Material Durability And Safety In Holographic Diffusers For Visual Applications, Matthew Hellis, Alan Casey, Edoardo Splendi, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

This study introduces novel holographic diffuser applications employing acrylamide- or diacetone acrylamide-based photopolymers, patterned within the volume on a micron scale by a single-beam holographic recording process. These diffusers have previously been presented as potential treatments for amblyopia and diplopia. This work has now been extended to spectrometric analysis to determine their properties under broadband light. Diffusive elements with higher diffusion efficiencies exhibited a marginal reduction (< 5%) in diffusion efficiency across most of the visible spectrum. Given the intended application of these holographic diffusers, cytotoxicity assessments were also performed. This is significant as there is a difference in toxicity between the crystalline acrylamide (classified as a category 3 material) and diacetone acrylamide (classified as a category 4 material). The findings indicated substantially lower toxicity in holograms produced with diacetone acrylamide-based photopolymer. The accelerated ageing of both formulations of holographic diffusers indicated that the acrylamide-based holographic diffusers did not reduce efficacy in the 292 days of ageing. The diacetone acrylamide-based holographic diffusers exhibited reduced efficacy by day 182. Despite this, both formulations have been shown to perform for prolonged periods as the treatment modality would require. These results emphasise that holographic diffusers exhibit minimal spectral impact, and longevity on the scale of treatment regimes which are crucial considerations for their prospective use case as treatments for amblyopia and diplopia.

Modeling Redistribution Of Nanozeolites In Holographic Recording, Dana Mackey, Jack Lyons Dr, Izabela Naydenova

Articles

Zeolite doped photopolymers have been studied experimentally due to their potential application in the develop- ment of optical sensors. It has been shown that dopant redistribution can be achieved by holographic recording and has a direct influence on the sensitivity of the recorded grating. To achieve better theoretical understanding of these processes, this paper proposes an extended photopolymerization-diffusion mathematical model for describing the dynamics of nanozeolite redistribution during recording in an acrylamide-based photopolymer. Using numerical simulations of this model, we investigate how recording conditions, dopant transport parameters, and initial load affect the refractive index modulation of the resulting photonic structure.

Holographic Multiplexing In A Photopolymerisable Hybrid Sol-Gel, Pamela Stoeva, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy

Articles

Holographic multiplexing techniques enhance functionality and information storage by leveraging the inherent selectivity of holograms. This is crucial for advancing holographic sensors, which excel in simultaneously detecting multiple parameters from a single input signal. This study explores the potential of the recent photopolymerisable hybrid sol-gel (PHSG) material for application in Space sensing systems through the investigation of its holographic angular multiplexing capabilities. For the first time, to the best of our knowledge, we report the successful recording of up to five angularly multiplexed gratings with diffraction efficiencies (DE) ≥ 15% in 187 ± 18 µm PHSG layers. A 3 mW/cm2 …

Modelling Hoe Performance With An Extended Source; Experimental Investigation Using Misaligned Point Sources, Jorge Lasarte, Kevin Murphy, Izabela Naydenova, Maria Victoria Collados, Jesús Atencia, Suzanne Martin

Articles

Holographic optical elements (HOEs) have the potential to enable more compact, versatile, and lightweight optical designs, but many challenges remain. Volume HOEs have the advantage of high diffraction efficiency, but they present both chromatic selectivity and chromatic dispersion, which impact their use with wide spectrum light sources. Single-color light emitting diode (LED) sources have a narrow spectrum that reduces these issues and this makes them better suited for use with volume HOEs. However, the LED source size must be taken into consideration for compact volume HOE-LED systems. To investigate the design limits for compact HOE-LED systems, a theoretical and experimental …

Optical Characterisation Of Holographic Diffusers And Bangerter Foils For Treatment Of Amblyopia, Matthew Hellis, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

Amblyopia is a significant issue for children worldwide, and current treatment methods have drawbacks that can hinder treatment effectiveness and/or patient experience. This study proposes a new treatment method using holographic diffusers while also comparing their optical characteristics to a current treatment method (Bangerter foils). Holographic diffusers were developed by optically patterning thin polymer layers on a micron scale. Two compositions of photopolymer (acrylamide and diacetone acrylamide based) are analysed herein. Characterisation shows that holographic diffusers of either composition can achieve a wide range of on-axis intensity reductions, allowing for precise and customisable treatment levels by altering recording exposure time …

Diethoxycarbonyl-Bodipys As Heavy-Atom-Free Photosensitizers For Holographic Recording In Cellulose Acetate Photopolymer, Aimee Sheehan, Tatsiana Mikulchyk, Catherine S.P. De Castro, Safakath Karuthedath, Wejdan Althobaiti, Metodej Dvoracek, Sabad-E Gul, Hugh Byrne, FréDéRic Laquai, Izabela Naydenova, Mikhail Filatov

Articles

A series of new heavy-atom-free photosensitizers based on 2,6-diethoxycarbonyl-BODIPY scaffold was designed and applied for holographic recording in a photopolymerizable material. Photoinduced electron transfer between the BODIPY and meso-aryl subunits, followed by the formation of BODIPY triplet excited states via spin-orbit charge transfer intersystem crossing (SOCT-ISC) was studied by steady-state and ultrafast pump-probe transient optical spectroscopy. Highly efficient photosensitization was observed for dyads bearing pyrene and anthracene substituents, which exhibited singlet oxygen generation quantum yields () of up to 94%. Charge transfer and SOCT-ISC were observed in non-polar solvent (toluene) due to the increased electron accepting ability of the diethoxycarbonyl-BODIPY. …

Color-Changing Reflection Hologram For Quality Assurance Of Therapeutic Ultrasound Systems, Tatsiana Mikulchyk, John Walsh, Jacinta Browne, Izabela Naydenova, Dervil Cody

Articles

The acoustic output of clinical therapeutic ultrasound equipment requires regular quality assurance (QA) testing to ensure the safety and efficacy of the treatment and that any potentially harmful deviations from the expected output power density are detected as soon as possible. A hologram, consisting of a reflection grating fabricated in an acrylate photopolymer film, has been developed to produce an immediate, visible, and permanent change in the color of the reconstructed hologram from red to green in response to incident ultrasound energy. The influence of the therapeutic ultrasound insonation parameters (exposure time, ultrasound power density, and proximity to the point …

Review-Electrode Kinetics And Electrolyte Stability In Vanadium Flow Batteries, Andrea Bourke, Daniela Oboroceanu, Nathan Quill, Catherine Lenihan, Maria Alhajji Safi Maria Alhajji Safi, Mallory A. Miller, Robert F. Savinell, Jesse S. Wainright, Varsha Sasikumarsp, Maria Rybalchenko, Pupak Amini, Niall Dalton, Robert P. Lynch, D. Noel Buckley

Articles

Two aspects of vanadium flow batteries are reviewed: electrochemical kinetics on carbon electrodes and positive electrolyte stability. There is poor agreement between reported values of kinetic parameters; however, most authors report that kinetic rates are faster for VIV/VV than for VII/VIII. Cycling the electrode potential increases the rates of both reactions initially due to roughening but when no further roughening is observed, the VII/VIII and VIV/VV reactions are affected oppositely by the pretreatment potential. Anodic pretreatment activates the electrode for the VII/VIII reaction, and deactivates it for VIV/VV. Three states of the carbon surface are suggested: reduced and oxidized states …

Limits Of Detection Of Mycotoxins By Laminar Flow Strips: A Review, Xinyi Zhao, Hugh Byrne, Christine M. O’Connor, James Curtin, Furong Tian

Articles

Mycotoxins are secondary metabolic products of fungi. They are poisonous, carcinogenic, and mutagenic in nature and pose a serious health threat to both humans and animals, causing severe illnesses and even death. Rapid, simple and low-cost methods of detection of mycotoxins are of immense importance and in great demand in the food and beverage industry, as well as in agriculture and environmental monitoring, and, for this purpose, lateral flow immunochromatographic strips (ICSTs) have been widely used in food safety and environmental monitoring. The literature to date describing the development of ICSTs for the detection of different types of mycotoxins using …

Normative Data On The Foveal Avascular Zone In A Young Healthy Irish Population Using Optical Coherence Tomography Angiography, Susan M. O'Shea, Veronica O'Dwyer, Grainne Scanlon

Articles

Purpose: To establish normative data on the size, shape and vascular profile of the foveal avascular zone (FAZ) in a young, healthy, Irish population, using the Cirrus 5000 HD-OCT. Certain diseases may alter FAZ appearance. Normative databases provide normal baseline values for comparison, thus improving diagnostic ability.

Methods: One hundred and fifty-four subjects aged 18–35 years old were recruited. Superficial FAZ area, diameter, circularity, ganglion cell layer, central macular thickness (CMT), vascular perfusion and density were measured using the Cirrus 5000. Axial length was measured with the IOL Master and blood pressure was measured using the Omron sphygmomanometer. …

Temperature-Sensitive Holograms With Switchable Memory, Muhammad Irfan Dr, Suzanne Martin Dr, Izabela Naydenova Prof

Articles

Abstract

Herein, the dynamics and reversibility of temperature-induced changes in volume phase holographic gratings (VPHGs) recorded in the low-toxicity self-processing photopolymer poly(N-isopropyl acrylamide) (poly-NIPA) are reported on. Transmission and reflection gratings are exposed to temperatures ranging 8–60 °C to study the effect of temperature on their properties. First, the role of the photopolymer chemical composition is investigated by comparing layers containing NIPA with those containing acrylamide (AA) and measuring the normalized diffraction efficiency (DE) at 60 °C; higher thermal sensitivity is observed for poly-NIPA gratings (24% drop) versus low sensitivity for AA gratings (2% increase). The impact of …

Combined Experimental And Modeling Analysis For Thedevelopment Of Optical Materials Suitable To Enhance Theimplementation Of Plasmonic-Enhanced Luminescent Down-Shifting Solutions On Existing Silicon-Based Photovoltaic Devices, James Walshe, Mihaela Girtan, Sarah Mccormack, John Doran, George Amarandei

Articles

The development of highly efficient solar collectors requires modulating the light interactions with the semiconducting materials. Incorporating luminescent species and metal nanoparticles within a semitransparent polymeric material (e.g., polymethyl methacrylate (PMMA)) leads to the formation of a plasmon-enhanced luminescent down-shifting (PLDS) layer, which offers a retrofittable approach toward expanding the wavelength range over which the conversion process can effectively occur. Adding antireflection coatings (ARCs) further controls the spectral response. However, with each additional component comes additional loss pathways. In this study, the losses related to light interactions with the PMMA and the ARCs have been investigated theoretically using a transfer …

Evaluation Of Postoperative Refractive Error Correction After Cataract Surgery, Ellen Konadu Antwi-Adjei, Emmanuel Owusu, Emmanuel Kobia-Acquah, Emmanuella Esi Dadzie, Emmanuel Anarfi, Seth Wanye

Articles

Suboptimal cataract surgery outcomes remain a challenge in most developing countries. In Ghana, about 2 million people have been reported to be blind due to cataract with about 20% new cases being recorded yearly. The aim of this study was to evaluate postoperative correction of refractive errors after cataract surgery in a selected eye hospital in Ashanti Region, Ghana. This was a retrospective study where medical records of patients (aged 40–100) who reported to an eye hospital in Ghana from 2013–2018 were reviewed. Included in the study were patients aged ≥40 years and patients with complete records. Data on patient …

Enhancing The Visibility Of Vernier Effect In A Tri-Microfiber Coupler Fiber Loop Interferometer For Ultrasensitive Refractive Index And Temperature Sensing, Fangfang Wei, Dejun Liu, Zhe Wang, Zhuochen Wang, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova

Articles

In this paper a Vernier effect based sensor is analyzed and demonstrated experimentally in a tri-microfiber coupler (Tri-MFC) and polarization-maintaining fiber (PMF) loop interferometer (Tri-MFC-PMF) to provide ultrasensitive refractive index and temperature sensing. The main novelty of this work is an analysis of parameters of the proposed Tri-MFC-PMF with the objective of determining the conditions leading to a strong Vernier effect. It has been identified by simulation that the Vernier effect is a primary factor in the design of Tri-MFC-PMF loop sensing structure for sensitivity enhancement. It is furthermore demonstrated experimentally that enhancing the visibility of the Vernier spectrum in …

Nis2 As A Broadband Saturable Absorber For Ultrafast Pulse Lasers, Pengfei Wang, Han Zhang, Yu Yin, Qiuyun Ouyang, Yujin Chen, Elfed Lewis, Gerald Farrell, Masaki Tokurakawa, Sulaiman Wadi Harun, Cong Wang, Shi Li

Articles

Nickel disulfide (NiS2) has recently been found to possess strong nonlinear saturable absorption properties. This feature is highly attractive for nonlinear photonics applications. Ultrafast pulse generation is successfully demonstrated in this article for both Ytterbium- and Erbium-doped fibre lasers using micro-fibre deposited nickel disulfide (NiS2) as a saturable absorber (SA). The fabricated SA device has a modulation depth of 23% at 1.06 μm and 30.8% at 1.55 μm. Stable dissipative soliton operation was achieved at 1064.5 nm with a pulse duration of 11.7 ps and another stable conventional soliton pulse train was also obtained at 1560.2 nm with a pulse …

Intense Mid-Infrared Emission At 3.9 Μm In Ho3+-Doped Zbya Glasses For Potential Use As A Fiber Laser, Haiyan Zhao, Ruicong Wang, Xin Wang, Shijie Jia, Yaxian Fan, Elfed Lewis, Gerald Farrell, Shunbin Wang, Pengfei Wang

Articles

Intense mid-infrared emission at 3.9 µm in Ho3+-doped ZBYA glasses with direct upper laser level (Ho3+ : 5 I5) pumping at a wavelength of 888 nm is reported for the first time, to the best of our knowledge. Spectroscopic parameters were determined using the Judd–Ofelt theory and the measured absorption spectrum. The maximum emission cross section of the Ho3+-doped ZBYA glass is estimated to be 2.7 × 10−21 cm2 at 3906 nm. Additionally, fluorescence spectra and lifetimes of ZBYA glasses with different Ho3+ ion doping concentrations were measured. The results provide theoretical and experimental basis for better selection of rare-earth-doped …

Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures, Ke Tian, Ruoning Wang, Meng Zhang, Xiafan Wang, Xin Wang, Guoyong Jin, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A low-cost optical fibre sensor based on two cascaded balloon-like bent fibre (BBF) structures for simultaneous displacement and temperature measurement is reported. The sensor is fabricated by cascading two balloon-like bent single-mode fibres (SMFs) which with different bending radii, generating two separate interference dips within a limited wavelength range. The wavelength of the two interference dips exhibits different responses to external displacement and temperature variations, hence simultaneous measurement of displacement and temperature is realized. Experimental results show that the proposed optical fibre sensor achieves a displacement sensitivity of −318.8 pm/μm and a temperature sensitivity of 47.4 pm/°C. Taking advantage of …

High-Sensitivity Temperature Sensor Based On Anti-Resonance In High-Index Polymer-Coated Optical Fiber Interferometers, Xiaokang Lian, Qiang Wu, Gerald Farrell, Yuliya Semenova

Articles

Compared to the multimode interference (MMI) effect, the anti-resonance (AR) effect does not rely on the multimode property of the optical waveguide. This Letter shows that fiber bending can suppress the MMI and can break the superposition of AR spectra of multiple modes in a high-index polymer-coated optical fiber interferometer based on a single-mode fiber-polymer-coated no-core fiber-single-mode fiber hetero-structure. This results in the dominance of the AR spectrum of an individual mode and consequently in periodic sharp transmission dips. As a result of this phenomenon and large thermo-optical and thermal expansion coefficients of the polymer, a compact, high-sensitivity and linear …

Stacked Volume Holographic Gratings For Extending The Operational Wavelength Range In Led And Solar Applications, Sanjay Keshri, Julia Marín-Sáez, Izabela Naydenova, Kevin Murphy, Jesús Atencia, Daniel Chemisana, Sean Garner, María-Victoria Collados, Suzanne Martin

Articles

A novel stacking procedure is presented for volume phase holographic gratings (VPHGs) recorded in photopolymer material using Corning Willow Glass as a flexible substrate in order to achieve broader angular and spectral selectivity in a diffractive device with high efficiency for solar and LED applications. For the first time to our knowledge, we have shown a device designed for use with a white LED that has the same input and output angles and high efficiency when illuminated by different wavelengths. In this paper, two VPHGs were designed, experimentally recorded, and tested when illuminated at normal incidence. The experimental approach is …

Birefringent Optofluidic Gratings, Sergio Calixto, Jose L. Garcia-Cordero, Diana F. Cedillo-Alcantar, Izabela Naydenova, Guillermo Garnica

Articles

A set of parallel microfluidic channels behaving as a diffraction grating operating in the Raman-Nath regime has been fabricated and studied. The diffraction efficiency of such structure can be tuned by selecting a liquid with a particular refractive index and/or optical anisotropy. Alternatively the optical properties of the liquid can be characterised by measuring the diffraction efficiency and the state of polarization of the diffracted beam. In this work, the microfluidic channels under study have been filled with penicillin molecules dissolved in water. Due to the chirality of the penicillin, the liquid has been found to have circular birefringence of …

Microfluidic Flow Direction And Rate Vector Sensor Based On A Partially Gold-Coated Tfbg, Changyu Shen, Dejun Liu, Xiaokang Lian, Tingting Lang, Chunliu Zhao, Yuliya Semenova, Jacques Albert

Articles

In microfluidic chips applications, the monitoring of the rate and the direction of a microfluidic flow is very important. Here, we demonstrate a liquid flow rate and a direction sensor using a partially gold-coated tilted fiber Bragg grating (TFBG) as the sensing element. Wavelength shifts and amplitude changes of the TFBG transmission resonances in the near infrared reveal the direction of the liquid flowing along the fiber axis in the vicinity of the TFBG due to a nanoscale gold layer over part of the TFBG. For a device length of 10 mm (and a diameter of 125 µm for easy …

Distribution Of Tm 3+ And Ni 2+ In Chalcogenide Glass Ceramics Containing Ga2s3 Nanocrystals: Influence On Photoluminescence Properties, Xiaosong Lu, Zhiqiang Lai, Jing Ren, Lukas Strizik, Tomas Wagner, Yanqiu Du, Gerald Farrell, Pengfei Wang

Articles

The distribution of Tm3+ and Ni2+ ions is unambiguously exhibited in 80GeS2-20Ga2S3 chalcogenide glass ceramics (GCs) containing Ga2S3 nanocrystals (NCs) by using advanced analytical transmission electron microscopy. Distinctively different distribution patterns of Tm3+ and Ni2+ ions are observed in the GCs obtained by controlled crystallization. The distribution of the dopants imposes strong influence on their optical properties which are revealed by absorption and photoluminescence (PL) spectra. Detailed discussions are given of the mechanisms of the crystallization-induced PL enhancement and quenching of the Tm3+ mid-infrared and Ni2+ near-infrared emissions, respectively.

All Fibre Q-Switched Thulium-Doped Fibre Laser Incorporating Thulium–Holmium Co-Doped Fibre As A Saturable Absorber, Shi Li, Elfed Lewis, Gerald Farrell, Ahmad Haziq Aiman Rosol, A.A. Latiff, Sulaiman Wadi Harun, Bingang Guo, Pengfei Wang

Articles

A novel all fibre Q-switched Thulium-doped fibre laser (TDFL) is reported which includes a short length of a Thulium–Holmiumco-doped fibre (THDF) as a saturable absorber. A high repetition rate (27.26 kHz) coupled with a low pulse width (19.06μs) is obtained for single wavelength Q-switched pulse operation at an output wavelength of 1911.5 nm using a pump power of 200 mW. Increasing the pump power from 200 mW to 700 mW results in the repetition rate increasing from 27.26 kHz to 99.67 kHz and the pulse width decreasing from 19.06μs to 920 ns. The centre wavelength of the single Q-switched pulse …

In-Fiber Temperature Sensor Based On Green Up-Conversion Luminescence In An Er3+-Yb3+ Co-Doped Tellurite Glass Microsphere, Meng Zhang, Angzhen Li, Jibo Yu, Xiaosong Lu, Shunbin Wang, Elfed Lewis, Gerald Farrell, Libo Yuan, Pengfei Wang

Articles

A novel, to the best of our knowledge, in-fiber temperature sensor based on green up-conversion (UC) luminescence in an Er3+-Yb3+" role="presentation" style="box-sizing: border-box; display: inline; font-size: 12.88px; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Er3+-Yb3+Er3+-Yb3+ co-doped tellurite glass microsphere is described. The tellurite glass microsphere is located firmly inside a suspended tri-core hollow-fiber (STCHF) structure. The pump light launched via a single-mode fiber (SMF) is passed through a section of multimode fiber, which is fusion spliced between the SMF …

Sns Optical Fiber Structure Sensor For Direct Detection Of The Phase Transition In C18h38 N-Alkane Material, Wei Han, Marek Rebow, Xiaokang Lian, Dejun Liu, Gerald Farrell, Qiang Wu, Yuliya Semenova

Articles

A singlemode-no-core-singlemode (SNS) fiber structure optical sensor for detecting the solid-liquid phase change in a phase change material: C18H38 n-alkane material (n-octadecane) is proposed and demonstrated. The transmission-type sensor probe consists of a short section of no-core fiber sandwiched between two sections of a singlemode fiber. Phase changes in n-octadecane are accompanied by large step-like variations of its refractive index (RI). Such a large discontinuous change of the n-octadecane’s RI during its phase transition, leads to the corresponding step-like change in the transmitted optical power that can reliably indicate the phase change of the sample in the vicinity of the …

Ultrabroadband Mid-Infrared Emission From Cr 2+ -Doped Infrared Transparent Chalcogenide Glass Ceramics Embedded With Thermally Grown Zns Nanorods, Xiaosong Lu, Zhiqiang Lai, Runan Zhang, Haitao Guo, Jing Ren, Lukas Strizik, Tomas Wagner, Gerald Farrell, Pengfei Wang

Articles

We report, for the first time to our knowledge, an ultrabroadband mid-infrared (MIR) emission in the range of 1800–2800 nm at room temperature from a Cr2+-doped chalcogenide glass ceramic embedded with pure hexagonal (wurtzite) β-ZnS nanorods and study the emission-dependent properties on the doping concentration of Cr2+. A new family of chalcogenide glasses based on (100 − x) Ge1.5As2S6.5 – x ZnSe (in mol.%) was prepared by melt-quenching method. The Cr2+: β-ZnS nanorods of ˜150 nm in diameter and ˜1 μm in length were grown in the Cr2+-doped glass after thermal annealing. The compositional variations of glass structures and optical …

A Twelve-Wavelength Thulium-Doped Fibre Laser Based On A Microfibre Coil Resonator Incorporating Black Phosphorus, Shi Li, Yu Yin, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A novel multi-wavelength continuous Thulium-doped fibre laser incorporating a microfibre coil resonator based on black phosphorus (MCR-BP) material has been successfully fabricated and demonstrated. A twelve-wavelength spectrum with 0.54 nm channel spacing has been achieved by simply adjusting the pump source power. A single peak extinction ratio of more than 40 dB was observed. The superior performance of the MCR-BP described in this article compared to conventional MCR based fibre lasers can be attributed the inclusion of the Black Phosphorous Material. The enhanced lasing is primarily due to the twin properties of the MCR-BP device combining a comb-like filter effect …