Wavefront Shaping Optimization Algorithms For Focusing Light Through a Multimode Fiber

Download

280522_MasterThesis_MT.pdf

Date

2022-5

Author

TABAK, MEHMET

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

228
views

149
downloads

Optical fibers are widely used to guide optical signals. Multi-mode fibers offer a greater bandwidth when compared to single-mode counterparts. The intensity at the end of a multi-mode fiber can be affected by mode-to-mode coupling and multi-mode interference. This can reduce the signal throughput. However, the total intensity at the end of the fiber can be modulated by shaping the input wavefront and providing increased signal levels. In our study, we show that focusing light inside the optical fiber is possible by wavefront shaping. There is a unique wavefront that focuses light inside the media at a given location. While the light moves in the particles, we adjust the wavefront dynamically using the spatial light modulator. Here, we experimentally evaluate and develop optimization algorithms for wavefront shaping that focuses light through a multi-mode fiber. These algoritmhs are continuous sequential (C), stepwise sequential (S), segmented (SE), hybrid Monte-Carlo continuous (MCC), hybrid stepwise continuous (SC) and hybrid segmented continuous (SEC). We analyze and compare these algorithms according to their performance: speed, regional enhancement, total enhancement. The continuous algorithm has reached to focus faster than others, the MCC algorithm is slowest with 46% lower than the C algorithm. The ranking of speed is C, SE, S, SC, SEC, MCC, in order. However, focus formation is much faster using the H-MCC algorithm. There is focus formation with enhancement 150 times than the initial value at 357 seconds for MCC. The focus is seen clearly at the target point. For regional enhancement, the C algorithms have higher performance than the stepwise with 1.1% and segmented 2.9%. For the total enhancement, the SC algorithm has increased the total transmisson 5.82 times than initial value. The ranking of total enhancement is follow: the C algorithm: 5.80, the S: 5.61, the SE: 5.47, the SEC: 4.97, MCC: 4.90.

Subject Keywords

Interference, Optical fiber, Optimization, Speckle Pattern, Wavefront Shaping

URI

https://hdl.handle.net/11511/97384

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Numerical simulations on stimulated raman scattering for fiber raman amplifiers and lasers using spectral methods Berberoğlu, Halil; Çakır, Serhat; Department of Physics (2007) Optical amplifiers and lasers continue to play its crucial role and they have become an indispensable part of the every fiber optic communication systems being installed from optical network to ultra-long haul systems. It seems that they will keep on to be a promising future technology for high speed, long-distance fiber optic transmission systems. The numerical simulations of the model equations have been already commercialized by the photonic system designers to meet the future challenges. One of the chal...
Photoluminescence specroscopy of CdS and GaSe Seyhan, Ayşe; Turan, Raşit; Department of Physics (2003) With the use of photoluminescence (PL) spectroscopy one can able to get a great deal of information about electronic structure and optical processes in semiconductors by the aid of optical characterization. Among various compound semiconductors, Cadmium Sulfide (CdS) and Gallium Selenide (GaSe) are interesting materials for their PL emissions. Particularly, due to its strong anisotropy, investigation of GaSe necessitates new experimental approaches to the PL technique. We have designed, fabricated and used ...
Wavefront shaping assisted design and application of effective diffractive optical elements providing spectral splitting and solar concentration: splicons Gün, Berk Nezir; Yüce, Emre; Department of Physics (2020-9) The diffractive optical elements that mainly concentrate light are primarily designed via numerical methods. These methods incur increased computational time as well as a lack of real-life conditions. Our experimental approach offers a new design method for SpliCon, a particular type of diffractive optical element that can spectrally split and concentrate broadband light (420 nm - 875 nm). We managed to form a programmable SpliCon by wavefront shaping via a phase-only spatial light modulator.The method we...
SNR CALCULATION METHOD FOR REMOTE SENSING SATELLITE IMAGING SYSTEMS Turkmenoglu, Mustafa; Sengul, Orhan; Demircioglu, Erdem (2013-06-01) Signal to Noise Ratio (SNR) is a metric used to link the image quality and radiometric performance of the remote sensing imaging systems. It is one of the remote sensing imaging system's design parameters that represents the image quality. SNR calculation and analysis should be carried out at design phase of remote sensing imaging systems. This calculation and analysis are crucial for confirmation of design success. It is important to show that the light flux reaching the sensor and the generated electrons ...
MgO/GaSe0.5S0.5 Heterojunction as Photodiodes and Microwave Resonators Qasrawi, Atef F.; Khanfar, Hazem K.; Hasanlı, Nızamı (2016-02-01) In this paper, a multifunctional operating optoelectronic device that suits visible light (VLC) and microwave communication systems is designed and characterized. The device which is composed of p-type MgO and n-type GaSe0.5S0.5 heterojunction is characterized by means of optical absorbance in the incident light energy (E) region of 3.5-1.1 eV, dark and illuminated current (I)-voltage (V) characteristics, and impedance spectra in the frequency range of 1M-1.8 GHz. Four types of lasers which generate light o...

Citation Formats

M. TABAK, “Wavefront Shaping Optimization Algorithms For Focusing Light Through a Multimode Fiber,” M.S. - Master of Science, Middle East Technical University, 2022.