Noise Performance of Single-Mode VCSELs: Dependence on Current Confinement and Optical Loss

We demonstrate a novel approach to the determination of optical loss coefficients in metal-coated fibers in a 0.4-1.9 μm wavelength range. It is based on measuring the change of temperature-dependent electrical resistance of the metal coating caused by laser radiation transmitted through the fiber. A number of single-mode and multimode metallized fibers were investigated using several laser sources operating in visible and near infrared ranges. The spectral dependencies of optical losses of copper-coated fibers were experimentally obtained. The region that corresponds to the minimum optical losses is located near 1 μm wavelength. The increase of radiation losses in 1.5-1.9 μm region is much steeper compared to polymer-coated fibers.

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Modeling and Analysis of Opto-Fluidic Sensor for Lab-On- a-Chip Application

10.20944/preprints201711.0154.v1 ◽

2017 ◽

Author(s):

Venkatesha M. ◽

Chaya B. M. ◽

Pattnaik P. K. ◽

Narayan K.

Keyword(s):

Continuous Flow ◽

Microfluidic Channel ◽

Optical Loss ◽

Lab On A Chip ◽

Single Mode ◽

Fluidic Channel ◽

Modeling And Analysis ◽

Micro Particles ◽

Sensing Applications ◽

Integrated Optical

In this work modeling and analysis of an integrated opto-fluidic sensor, with a focus on achievement of single mode optical confinement and continuous flow of micro particles in the microfluidic channel for Lab-on-a Chip (LOC) sensing application is presented. This sensor consists of integrated optical waveguides, microfluidic channel among other integrated optical components. A continuous flow of micro particles in a narrow fluidic channel is achieved by maintaining the two sealed chambers at different temperatures and by maintaining a constant pressure of 1Pa at the centroid of narrow fluidic channel geometry. The analysis of silicon on insulator (SOI) integrated optical waveguide at an infrared wavelength of 1550nm for single mode sensing operation is presented. The optical loss is found to be 0.0005719dB/cm with an effective index of 2.2963. The model presented in this work can be effectively used to detect the nature of micro particles and continuous monitoring of pathological parameters for sensing applications.

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Акустооптические модуляторы с расширенной частотной полосой для волоконно-оптических линий

Журнал технической физики ◽

10.21883/jtf.2021.06.50874.330-20 ◽

2021 ◽

Vol 91 (6) ◽

pp. 1021

Author(s):

В.М. Епихин ◽

А.В. Рябинин

Keyword(s):

Optical Fibers ◽

Frequency Band ◽

Switching Time ◽

Optical Loss ◽

Single Mode ◽

Operating Mode ◽

Center Frequency ◽

Frequency Shifter ◽

Focused Beam ◽

Good Agreement

A modulator-frequency shifter with single-mode optical fibers for a radiation wavelength of 1064 nm has been developed and manufactured. The light beam was focused in the center of the sound column. Modulator switching time ≃ 18 ns. Operating mode: pulse, continuous. Total optical loss at center frequency: -3.2 dB. An expression for the frequency band of reception of the modulator is obtained. The estimates are in good agreement with the experimental data ≃ 40 MHz. It is shown that the use of a scheme with a focused beam makes it possible to implement a modulator with a minimum switching time ≃ (2-3) ns and a receiving frequency band ≃ (200-300) MHz.

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Research of multisensor characteristics based on optical fiber

Doklady BGUIR ◽

10.35596/1729-7648-2021-19-1-70-78 ◽

2021 ◽

Vol 19 (1) ◽

pp. 70-78

Author(s):

A. O. Zenevich ◽

S. V. Zhdanovich ◽

H. V. Vasilevski ◽

A. A. Lagutik ◽

T. G. Kovalenko ◽

...

Keyword(s):

Optical Fiber ◽

Minimum Distance ◽

Optical Radiation ◽

Radiation Power ◽

Optical Loss ◽

Single Mode ◽

Optical Reflectometry ◽

Optimal Values ◽

The Impact ◽

To Receive

The research results of multisensors based on optical fiber, the principle of which is to change the conditions of propagation of optical radiation in the optical fiber in the places where macro-bends are formed at the points of impact, are presented in the paper. The formation of macro-bends leads to an additional attenuation of the power of optical radiation propagating through the optical fiber. A single-mode optical fiber was used with the parameters, which are supported by numerous manufacturers and comply with the recommendations of ITU-T G.655. The measurements were carried out for four wavelengths of optical radiation (1310, 1490, 1550, 1625 nm), corresponding to the transparency windows of the optical loss spectrum of the optical fiber. Using optical reflectometry methods, it was determined that the amount of attenuation of optical radiation of each macro-bend formed at the point of action of the multisensor does not depend on the number of simultaneously formed macro-bends and also does not depend on the location of the point of action along the length of the multisensor. The dependences of the attenuation of the optical radiation power introduced by the macro-bends of the optical fiber on the radius, length, or angle of the macro-bends formed at the multisensory impact points are determined experimentally. The obtained dependences also allow one to determine the optimal parameters of the formed macro-bends of the multisensor to obtain the maximum range of attenuation change for each value of the wavelength. The values of the minimum distance between the impact points, the maximum number of impact points and the optimal values of the radius and angle of the optical fiber macro-bend at the impact points are determined. The results obtained provide opportunities to continue the development of multisensors that allow us to receive information about parameters from several impact points, that are located on a single optical fiber, simultaneously.

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Current confinement in EP-VECSELs for high power single-mode operation suitable for passive mode-locking

10.1117/12.921522 ◽

2012 ◽

Cited By ~ 1

Author(s):

Imad Dahhan ◽

Yohan Barbarin ◽

Martin Hoffmann ◽

Wolfgang P. Pallmann ◽

Christian Zaugg ◽

...

Keyword(s):

High Power ◽

Single Mode ◽

Mode Locking ◽

Passive Mode ◽

Single Mode Operation ◽

Mode Operation ◽

Current Confinement

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Fused Coupler Optical Switch Using a Photochromic Material

MRS Proceedings ◽

10.1557/proc-244-245 ◽

1991 ◽

Vol 244 ◽

Author(s):

Yuji Kobayashi ◽

Toshifumi Hosoya ◽

Tsuyoshi Nonaka ◽

Yasuo Matsuda

Keyword(s):

Optical Switch ◽

Refractive Index Change ◽

Optical Loss ◽

Single Mode ◽

Photochromic Compound ◽

Coupling Region ◽

Index Change ◽

Optical Output ◽

Wavelength Light ◽

Cladding Material

ABSTRACTAn optical switch based on a single-mode fused coupler has been fabricated. The switch is worked by light induced refractive index change of an organic photochromic compound as cladding material in the coupling region. The splitting ratio of optical output at 1.3 μ m wavelength light can change 44.5%. The optical loss in the switch is less than 0.4

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Эффект насыщающегося поглотителя в длинноволновых вертикально-излучающих лазерах, реализованных по технологии спекания

Письма в журнал технической физики ◽

10.21883/pjtf.2020.24.50430.18522 ◽

2020 ◽

Vol 46 (24) ◽

pp. 49

Author(s):

С.А. Блохин ◽

М.А. Бобров ◽

А.А. Блохин ◽

А.П. Васильев ◽

А.Г. Кузьменков ◽

...

Keyword(s):

Optical Power ◽

Single Mode ◽

Threshold Current ◽

Lasing Threshold ◽

Cavity Surface ◽

Lateral Direction ◽

Vertical Cavity Surface ◽

Current Confinement ◽

Emitting Lasers ◽

Height Step

Vertical-cavity surface-emitting lasers emitting at the spectral range of 1.55 µm based on heterostructures with a buried tunnel junction (BTJ) with a height step of 15 nm are studied. The devices are realized using wafer fusion technique of heterostructures grown by molecular beam epitaxy and demonstrate a single-mode lasing regime at the 8 μm BTJ-diameter. With a decrease in the BTJ-diameter, a sharp increase in the threshold current, accompanied by an abrupt increase in the output optical power and resonance frequency at the lasing threshold are observed. Stable single-mode lasing is due to the smoothing of the boundary of the overgrown surface relief, which leads to a smooth change in the profile of the effective refractive index in the lateral direction, while maintaining effective current confinement, which makes it possible to significantly reduce the transverse optical confinement factor for high-order modes even at large BTJ-diameter. However, at small BTJ-diameter, it also leads to the formation of a saturable absorber in the non-pumped parts of the active region.

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Bend loss fiber optics design based on sinusoidal and ellipse configurations

Optica Applicata ◽

10.37190/oa210301 ◽

2021 ◽

Vol 51 (3) ◽

Author(s):

Noor Azie Azura Mohd Arif ◽

Dilla Durhya Burhanuddin ◽

Sahbudin Shaari ◽

Abang Annuar Ehsan

Keyword(s):

Fiber Optics ◽

Optical Fibers ◽

Optical Loss ◽

Single Mode ◽

Fiber Optic Sensor ◽

Curvature Radius ◽

Sensor Applications ◽

Bending Loss ◽

Bending Radius ◽

Bending Sensor

Bending losses in optical fibers comprise one of the extrinsic attenuations that contribute to optical loss and they are essential for optical fiber bending sensor applications. This work investigated the optical loss in a standard single-mode step-index fiber optics due to fiber bending at 1550 nm wavelength. Variations in macro-bending loss with curvature radius and turn number have been measured. Curvature radius and turn number are examined for sinusoidal and elliptical shaped bending configurations. It has been found that the loss increases as the bending radius and number of turns increase. The result also showed that elliptical shaped bending configuration produced more loss in contrast to that of sinusoidal shaped at bending angles of 180° and 360°. The study on the macro-bending loss in terms of curvature radius and turn number for both elliptical and sinusoidal shaped bending configurations is beneficial for future fiber optic sensor applications.

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