scholarly journals On-chip arbitrary-mode spot size conversion

Nanophotonics ◽  
2020 ◽  
Vol 9 (14) ◽  
pp. 4365-4372
Author(s):  
Wei Qi ◽  
Yu Yu ◽  
Xinliang Zhang
Keyword(s):  
Spot Size ◽  
Expansion Ratio ◽  
Fourier Optics ◽  
Graded Index ◽  
Beam Expander ◽  
Single Lens ◽  
Optical Modes ◽  
On Chip ◽  
Integrated Device ◽  
F System

AbstractManipulating on-chip optical modes via components in analogy with free-space devices provides intuitional light control, and this concept has been adopted to implement single-lens–assisted spot size conversion using integrated device. However, the reported schemes have been demonstrated only for fundamental mode, while high-order or irregular modes are preferred in specific applications. The 4-f system is widely used in Fourier optics for optical information processing. Under the inspiration of the 4-f system and the beam expander in bulk optics, a spot size converter (SSC) with two metamaterial-based graded-index waveguides is proposed and demonstrated. The proposed device is capable of widening an arbitrary mode while preserving its profile shape. Compared with conventional SSC using adiabatic taper, the footprint can be reduced by 91.5% under a same intermode crosstalk. Experimentally, an expansion ratio of five is demonstrated for regular modes. Furthermore, for an irregular mode, the functionality is numerically verified without structure modification. This work offers a universal solution to on-chip spot size conversion and may broaden the on-chip application prospects of Fourier optics.

scholarly journals Simulation Study on Optically Designed Refractive Beam Expander for Nd: YAG Laser Harmonics for 7 Km Detection Range

2014 ◽  
Vol 11 (2) ◽  
pp. 742-747
Author(s):  
Baghdad Science Journal
Keyword(s):  
Harmonic Generation ◽  
Simulation Study ◽  
Second Harmonic ◽  
Spot Size ◽  
Expansion Ratio ◽  
Detection Range ◽  
Yag Laser ◽  
Third Harmonic ◽  
Received Power ◽  
Beam Expander

The simulation study has been conducted for the harmonics of Nd: YAG laser, namely the second harmonic generation SHG, the third harmonic generation THG, and the fourth harmonic generation FHG. Determination of beam expander's expansion ratio for specific wavelength and given detection range is the key in beam expander design for determining minimum laser spot size at the target. Knowing optimum expansion ratio decreases receiving unit dimensions and increases its performance efficiency. Simulation of the above mentioned parameters is conducted for the two types of refractive beam expander, Keplerian and Galilean. Ideal refractive indices for the lenses are chosen adequately for Nd: YAG laser harmonics wavelengths, so that increasing transmission of laser beam, consequently the received power to the detector for practical convenience.

Scattering detection using a photonic-microfluidic integrated device with on-chip collection capabilities

2013 ◽  
Vol 35 (2-3) ◽  
pp. 271-281 ◽  
Author(s):  
Benjamin R. Watts ◽  
Zhiyi Zhang ◽  
Chang Qing Xu ◽  
Xudong Cao ◽  
Min Lin
Keyword(s):  
On Chip ◽  
Integrated Device

Graded-index fiber on-chip absorption spectroscopy

2021 ◽  
Author(s):  
Nicolas Riesen ◽  
Kamalpreet Gill ◽  
Craig Priest ◽  
Nicholas Phillips ◽  
Bin Guan ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Graded Index ◽  
On Chip

Study on Coupling of Step and Graded Index Single Mode Optical Fiber Considering the Transverse Misalignment

2020 ◽  
Vol 8 (2) ◽  
pp. 78-82
Author(s):  
Prosenjit Roy Chowdhury ◽  
◽  
Keyword(s):  
Optical Fiber ◽  
Communication Systems ◽  
Structural Parameters ◽  
Fractional Power ◽  
Single Mode ◽  
Spot Size ◽  
Fiber Coupling ◽  
Fundamental Parameters ◽  
Graded Index ◽  
Wide Range

"Advance design and day to day up-gradation of communication system is the requirement of international telecommunication. The optical communication systems involve the effective fiber coupling or splicing to meet the need of long communication channel. When the studies on both the intensive and extensive properties of optical fiber are exploring new research horizons, the effectiveness of such systems can be calibrated with transmission parameters like transmitted fractional power, which is a function of ‘spot size’ as well. Our study of fiber junctions based on fundamental parameters like wavelength, fiber profile index etc. has touched some unrevealed areas and explored some interesting results. The profile index of optical fiber has received less attention compared to other structural parameters of optical fiber but our study at important wavelengths for different profiles has shown that the less-used fiber profiles has some interesting premier outcomes, which can introduce some significant impact on optical fiber based system design and engineering. We have observed almost frequency or wavelength independent transmitted fractional power around the most used 1.55 micrometer wavelengths at some rarely used fiber profile index. Our study predicts the best and worst fiber profiles for transmitted fractional power (T ), at the same time, we have observed the fiber profile index independent region for a band of ‘T’ values. The reporting and its approach are found to be premier in this field. So, our work is reporting a comparison of effective fiber-to-fiber coupling, based on fiber profile index of different fibers. It is also giving a clear view of the wavelength dependency of effective fiber coupling for different fibers having wide range of graded fiber profiles."

APPLICATION AND PERFORMANCE EVALUATION FOR THE DMS SYSTEM IN THE SLS PROCESS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1833-1838 ◽  
Author(s):  
DONG SOO KIM ◽  
SUNG WOO BAE ◽  
KYUNG HYUN CHOI
Keyword(s):  
Processing Time ◽  
Solid Freeform Fabrication ◽  
Selective Laser Sintering ◽  
Spot Size ◽  
Laser Sintering ◽  
Processing Efficiency ◽  
Freeform Fabrication ◽  
Beam Expander ◽  
Scan Path ◽  
And Performance

A Solid Freeform Fabrication (SFF) system using Selective Laser Sintering (SLS) is currently recognized as a leading process and SLS extends the applications to machinery and automobiles due to the various materials employed. Especially, accuracy and processing time are very important factors when the desired shape is fabricated with Selective Laser Sintering (SLS), one of Solid Freeform Fabrication (SFF) system. In the convectional SLS process, laser spot size is fixed during laser exposing on the sliced figure. Therefore, it is difficult to accuracy and rapidly fabricates the desired shape. In this paper, to deal with those problems a SFF system having ability of changing spot size is developed. The system provides high accuracy and optimal processing time. Specifically, a variable beam expander is employed to adjust spot size for different figures on a sliced shape. Therefore, design and performance estimation of the SFF system employing a variable beam expander are achieved and the mechanism will be addressed to measure the real spot size generated from the variable beam expander. Also, the reduction of total processing time is an important issue in SFF system. A digital mirror system (DMS) is a system which scans the laser beam with different spot size. The spot size is selected based on the slicing section to decrease and accuracy of the process time and improve the processing efficiency. In this study, the optimal scan path generation for DMS will be addressed, and this development will improve the whole processing efficiency and accuracy through the scan efficiency by considering the existing scan path algorithm and heat energy distribution.

scholarly journals Controlling light’s helicity at the source: orbital angular momentum states from lasers

2017 ◽  
Vol 375 (2087) ◽  
pp. 20150436 ◽  
Author(s):  
Andrew Forbes
Keyword(s):  
Angular Momentum ◽  
Solid State ◽  
Orbital Angular Momentum ◽  
Laser Cavity ◽  
Solid State Lasers ◽  
On Demand ◽  
Twisted Light ◽  
Optical Modes ◽  
On Chip

Optical modes that carry orbital angular momentum (OAM) are routinely produced external to the laser cavity and have found a variety of applications, thus increasing the demand for integrated solutions for their production. Yet such modes are notoriously difficult to produce from lasers due to the strict symmetry requirements for their creation, together with the need to break the degeneracy in helicity. Here, we review the progress made since 1992 in producing such twisted light modes directly at the source, from gas to solid-state lasers, bulk to integrated on-chip solutions, through to generic devices for on-demand OAM in both scalar and vector forms. This article is part of the themed issue ‘Optical orbital angular momentum’.

scholarly journals STM Light Emission and I(V) study of single gold nanoantenna

2021 ◽  
Vol 2086 (1) ◽  
pp. 012103
Author(s):  
V A Shkoldin ◽  
D V Levedev ◽  
A M Mozharov ◽  
D V Permyakov ◽  
L N Dvoretckaia ◽  
...  
Keyword(s):  
Light Emission ◽  
Local Density ◽  
Optical Data ◽  
Light Emitters ◽  
Current Voltage ◽  
Optical Modes ◽  
Metal Tip ◽  
On Chip ◽  
Stm Light Emission ◽  
Photon Generation

Abstract Hight-speed optical nanoemitters are of importance for on-chip optical data processing. A tunnel junctions can be a base for such light emitters, however such structures suffer from low quantum efficiency. One of the ways to improve efficiency of tunneling electron energy to photon generation conversion is the increase of the local density of optical states by using of optical nanoantennas. In this work, we study optoelectronic properties of single gold nanodisc with high spatial resolution. We show nonuniform distribution of electromagnetic near-fields of nanodisk, which is consistent with nanoantenna optical modes. And we demonstrate direct correlation between nanoantenna optical states and features on current-voltage characteristics of tunnel junction between metal tip and nanodisk.

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