1
|
Paz-Buclatin F, Perera-Suárez Y, Martín IR, Ríos S, de Varona O, Ródenas A, Martin LL. Experimental and Numerical Validation of Whispering Gallery Resonators as Optical Temperature Sensors. SENSORS (BASEL, SWITZERLAND) 2022; 22:7831. [PMID: 36298181 PMCID: PMC9609393 DOI: 10.3390/s22207831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 06/16/2023]
Abstract
This study experimentally and numerically validates the commonly employed technique of laser-induced heating of a material in optical temperature sensing studies. Furthermore, the Er3+-doped glass microspheres studied in this work can be employed as remote optical temperature sensors. Laser-induced self-heating is a useful technique commonly employed in optical temperature sensing research when two temperature-dependent parameters can be correlated, such as in fluorescence intensity ratio vs. interferometric calibration, allowing straightforward sensor characterization. A frequent assumption in such experiments is that thermal homogeneity within the sensor volume, that is, a sound hypothesis when dealing with small volume to surface area ratio devices such as microresonators, but has never been validated. In order to address this issue, we performed a series of experiments and simulations on a microsphere supporting whispering gallery mode resonances, laser heating it at ambient pressure and medium vacuum while tracking the resonance wavelength shift and comparing it to the shift rate observed in a thermal bath. The simulations were done starting only from the material properties of the bulk glass to simulate the physical phenomena of laser heating and resonance of the microsphere glass. Despite the simplicity of the model, both measurements and simulations are in good agreement with a highly homogeneous temperature within the resonator, thus validating the laser heating technique.
Collapse
Affiliation(s)
- Franzette Paz-Buclatin
- Departamento de Física, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain
| | - Ylenia Perera-Suárez
- Departamento de Física, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain
| | - Inocencio R. Martín
- Departamento de Física, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain
| | - Susana Ríos
- Departamento de Física, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain
| | - Omar de Varona
- Departamento de Física, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain
| | - Airán Ródenas
- Departamento de Física, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain
| | - Leopoldo L. Martin
- Departamento de Física, Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain
- Instituto Universitario de Estudios Avanzados (IUdEA), Universidad de La Laguna, Apdo. 456, E-38200 San Cristóbal de La Laguna, Spain
| |
Collapse
|
2
|
Gu F, Cao H, Song Z, Xie P, Zhao J, Liu J. Dot-coded structured light for accurate and robust 3D reconstruction. APPLIED OPTICS 2020; 59:10574-10583. [PMID: 33361992 DOI: 10.1364/ao.403624] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
Speckle dots have the advantage of easy projection, which makes them good candidate features of structured light (SL) cameras, such as Kinect v1. However, they generally yield poor accuracy due to block matching. To improve their accuracy, this paper proposes a dot-coded SL, the coding information of which is added into dot distribution. Some of the dots are arranged regularly to provide easy-to-locate corner features, while others are specially designed to form different shapes of unique identification. A Gaussian-cross module and a simplified ResNet have been proposed to conduct robust decoding. Various experiments are performed to verify the accuracy and robustness of our framework.
Collapse
|
3
|
Frigenti G, Farnesi D, Nunzi Conti G, Soria S. Nonlinear Optics in Microspherical Resonators. MICROMACHINES 2020; 11:E303. [PMID: 32183230 PMCID: PMC7142417 DOI: 10.3390/mi11030303] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 01/01/2023]
Abstract
Nonlinear frequency generation requires high intensity density which is usually achieved with pulsed laser sources, anomalous dispersion, high nonlinear coefficients or long interaction lengths. Whispering gallery mode microresonators (WGMRs) are photonic devices that enhance nonlinear interactions and can be exploited for continuous wave (CW) nonlinear frequency conversion, due to their capability of confine light for long time periods in a very small volume, even though in the normal dispersion regime. All signals must be resonant with the cavity. Here, we present a review of nonlinear optical processes in glass microspherical cavities, hollow and solid.
Collapse
Affiliation(s)
- Gabriele Frigenti
- Centro Fermi—Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Compendio del Viminale, Piazza del Viminale 1, 00184 Roma, Italy; (G.F.); (G.N.C.)
- CNR-IFAC, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, via Madonna del Piano 10, I50019 Sesto Fiorentino (FI), Italy;
- Laboratorio Europeo di Spettroscopia Nonlineare (LENS) - Università degli Studi di Firenze, via Nello Carrara 1, I50019 Sesto Fiorentino (FI), Italy
| | - Daniele Farnesi
- CNR-IFAC, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, via Madonna del Piano 10, I50019 Sesto Fiorentino (FI), Italy;
| | - Gualtiero Nunzi Conti
- Centro Fermi—Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Compendio del Viminale, Piazza del Viminale 1, 00184 Roma, Italy; (G.F.); (G.N.C.)
- CNR-IFAC, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, via Madonna del Piano 10, I50019 Sesto Fiorentino (FI), Italy;
| | - Silvia Soria
- CNR-IFAC, Istituto di Fisica Applicata “Nello Carrara”, Consiglio Nazionale delle Ricerche, via Madonna del Piano 10, I50019 Sesto Fiorentino (FI), Italy;
| |
Collapse
|
4
|
Runowski M, Martín IR, Sigaev VN, Savinkov VI, Shakhgildyan GY, Lis S. Luminescent-plasmonic core–shell microspheres, doped with Nd3+ and modified with gold nanoparticles, exhibiting whispering gallery modes and SERS activity. J RARE EARTH 2019. [DOI: 10.1016/j.jre.2018.10.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
5
|
Labrador-Páez L, Soler-Carracedo K, Hernández-Rodríguez M, Martín IR, Carmon T, Martin LL. Liquid whispering-gallery-mode resonator as a humidity sensor. OPTICS EXPRESS 2017; 25:1165-1172. [PMID: 28158001 DOI: 10.1364/oe.25.001165] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We experimentally demonstrate the high sensitivity of a novel liquid state, whispering-gallery-mode optical resonator to humidity changes. The optical resonator used consists of a droplet made of glycerol, a transparent liquid that enables high optical quality factor, doped with fluorescent material. As glycerol is highly hygroscopic, the refractive index and radius of the droplet change with ambient humidity. This produces a shift on the whispering gallery mode's wavelengths, which modulates the emission of the fluorescent material. This device shows an unpreceded sensitivity of 10-3 per relative humidity percent.
Collapse
|
6
|
Lai CC, Lo CY, Nguyen DH, Huang JZ, Tsai WS, Ma YR. Atomically smooth hybrid crystalline-core glass-clad fibers for low-loss broadband wave guiding. OPTICS EXPRESS 2016; 24:20089-20106. [PMID: 27607618 DOI: 10.1364/oe.24.020089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We demonstrate direct evidence for the first realization of atomically smooth sapphire crystalline fiber cores with a surface variation of only ~1.9 Å. The hybrid glass-clad crystalline cores were grown by a laser-based fiber drawing technique. Because of the improvement in crystal fiber quality, we were able, for the first time, to comprehensively and quantitatively elucidate the correlation between fiber nanostructure and optical loss. We also experimentally demonstrated that high-temperature treatment has a significant impact on defect relaxation and promotes excellent crystallinity, and hence enables low-loss optical wave guiding. The experimentally measured propagation losses in the order of 0.01-0.1 dB/cm are the lowest ever reported among conventional Ti:sapphire channel waveguides and ultrafast-laser-inscribed waveguides, and agree well with the theory. Through experiments and numerical calculation, we have demonstrated that low threshold and high efficiency of Ti:sapphire crystal fiber lasers are possible with the atomic-level roughness, low-loss propagation, and high crystallinity of the Ti:sapphire crystalline core.
Collapse
|
7
|
Martín LL, Pérez-Rodríguez C, Haro-González P, Martín IR. Whispering gallery modes in a glass microsphere as a function of temperature. OPTICS EXPRESS 2011; 19:25792-25798. [PMID: 22273972 DOI: 10.1364/oe.19.025792] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Microspheres of Nd3+ doped barium titano silicate glass were prepared and the whispering gallery mode resonances were observed in a modified confocal microscope. A bulk sample of the same glass was calibrated as temperature sensor by the fluorescence intensity ratio technique. After that, the microsphere was heated by laser irradiation process technique in the microscope and the surface temperature was estimated using the fluorescence intensity ratio. This temperature is correlated with the displacement of the whispering gallery mode peaks, showing an average red-shift of 10 pm/K in a wide range of surface temperatures varying from 300 K to 950K. The limit of resolution in temperature was estimated for the fluorescence intensity ratio and the whispering gallery mode displacement, showing an improvement of an order of magnitude for the second method.
Collapse
Affiliation(s)
- L L Martín
- Departamento de Física Fundamental y Experimental, Universidad de La Laguna, S/C de Tenerife, Spain.
| | | | | | | |
Collapse
|