Calculation of the overlap factor and  correction of near-field signal of the off-axis lidar based on the Gaussian mode of laser beam

In this paper we image the highly confined long range plasmons of a nanoscale metal stripe waveguide using quantum emitters. Plasmons were excited using a highly focused 633 nm laser beam and a specially designed grating structure to provide stronger incoupling to the desired mode. A homogeneous thin layer of quantum dots was used to image the near field intensity of the propagating plasmons on the waveguide. We observed that the photoluminescence is quenched when the QD to metal surface distance is less than 10 nm. The optimised spacer layer thickness for the stripe waveguides was found to be around 20 nm. Authors believe that the findings of this paper prove beneficial for the development of plasmonic devices utilising stripe waveguides.

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Simulations of the Near-Field Enhancement on AFM Tip Irradiated by Annular Laser Beam

IEEE Transactions on Nanotechnology ◽

10.1109/tnano.2019.2938614 ◽

2019 ◽

Vol 18 ◽

pp. 979-982

Author(s):

Xiwen Lu ◽

Lijun Yang ◽

Hui Xie ◽

Zhan Yang ◽

Jianlei Cui ◽

...

Keyword(s):

Laser Beam ◽

Near Field ◽

Field Enhancement ◽

Annular Laser

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Lidar Overlap Function Determination Using the Raman Lidar Signals

EPJ Web of Conferences ◽

10.1051/epjconf/202023707018 ◽

2020 ◽

Vol 237 ◽

pp. 07018

Author(s):

Jaswant ◽

Shishir Kumar Singh ◽

Radhakrishnan S.R. ◽

Devesh Shukla ◽

Chhemendra Sharma

Keyword(s):

Optical Properties ◽

Simple Technique ◽

Near Field ◽

Lower Atmosphere ◽

Raman Lidar ◽

Lidar System ◽

Field Range ◽

The Mean ◽

Overlap Factor

The determination of vertical distribution of optical properties of clouds and aerosols using the lidar system is affected by the incomplete overlap between the field of view of transmitter i.e. laser beam & the receiver in the near‐field range. Thus, the study of vertical profiles of aerosol optical properties in the lower atmosphere is erroneous without the correction of lidar overlap function. Here we have analysed the effect of overlap using a simple technique proposed by Ansmann and Wandinger to determine overlap function. We have determined the overlap factor for 5 different days of June 2016 and then calculated the mean overlap profile and determined the relative deviation of each day with respect to mean overlap factor. Results reveal that the complete overlap was achieved beyond 300 meters.

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Self-induced thermal distortion in the near field for a laser beam in a moving medium

IEEE Journal of Quantum Electronics ◽

10.1109/jqe.1971.1076598 ◽

1971 ◽

Vol 7 (2) ◽

pp. 63-73 ◽

Cited By ~ 67

Author(s):

F. Gebhardt ◽

D. Smith

Keyword(s):

Laser Beam ◽

Near Field ◽

Thermal Distortion ◽

Moving Medium

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Analysis of near field characteristics of a diffractive optical laser beam profile shaper using a high accuracy finite difference time domain method

International Optical Design Conference ◽

10.1364/iodc.2002.iwc3 ◽

2002 ◽

Author(s):

S. Banerjee ◽

T. Yatagai ◽

J. B. Cole

Keyword(s):

Finite Difference ◽

Laser Beam ◽

Time Domain ◽

Finite Difference Time Domain ◽

Near Field ◽

High Accuracy ◽

Time Domain Method ◽

Laser Beam Profile ◽

Difference Time ◽

Optical Laser

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Photoresponsive polymers for topographic simulation of the optical near-field of a nanometer sized gold tip in a highly focused laser beam

Optics Express ◽

10.1364/opex.13.003619 ◽

2005 ◽

Vol 13 (10) ◽

pp. 3619 ◽

Cited By ~ 20

Author(s):

Yann Gilbert ◽

Renaud Bachelot ◽

Alexandre Vial ◽

Gilles Lerondel ◽

Pascal Royer ◽

...

Keyword(s):

Laser Beam ◽

Near Field ◽

Gold Tip

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Hemi-Ellipsoidal microlensed fiber based on polishing and polymer technology

Engineering Research Express ◽

10.1088/2631-8695/ac3a58 ◽

2021 ◽

Author(s):

Nadjiba Boulaiche ◽

Philippe Rochard ◽

Assia Guessoum ◽

Nacer-Eddine Demagh ◽

Monique Thual

Keyword(s):

Laser Beam ◽

Near Field ◽

Single Mode ◽

Experimental Results ◽

Advanced Technology ◽

Mode Field ◽

Measurement Results ◽

Mechanical Micromachining

Abstract This paper represents a development of a new advanced technology to fabricate and characterize micro-collimators with hemi-ellipsoidal microlenses at single-mode fibers outputs. The proposed method utilizes the controlled mechanical micromachining technique based on the variation of the speed of the fiber around its axis in both X and Y directions followed by the injection of a quantity of polydimethylsiloxane (PDMS) to form the hemi-ellipsoidal microlenses. The experimental results show that this technique allows to obtain a wide variety of ellipticity diameters ratios from 0.68 to 0.84. An elliptical ratio of radii of curvature Ry/Rx in a range of 0.51 at 0.86 is also obtained. In this investigation a mode field diameters MFD in an interval between 3.26 µm and 9.93 µm have been realized. The measurement results demonstrate that the proposed technology allows to fabricate hemi-ellipsoidal microlenses having an MFD ellipticity ratios of about 0.60 to 0.97 in near field promising for micro-collimator suitable to match an elliptical laser beam to the circular one of a fiber.

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