Comparing different nonlinearities in readout systems for optical neuromorphic computing networks

AbstractNonlinear activation is a crucial building block of most machine-learning systems. However, unlike in the digital electrical domain, applying a saturating nonlinear function in a neural network in the analog optical domain is not as easy, especially in integrated systems. In this paper, we first investigate in detail the photodetector nonlinearity in two main readout schemes: electrical readout and optical readout. On a 3-bit-delayed XOR task, we show that optical readout trained with backpropagation gives the best performance. Furthermore, we propose an additional saturating nonlinearity coming from a deliberately non-ideal voltage amplifier after the detector. Compared to an all-optical nonlinearity, these two kinds of nonlinearities are extremely easy to obtain at no additional cost, since photodiodes and voltage amplifiers are present in any system. Moreover, not having to design ideal linear amplifiers could relax their design requirements. We show through simulation that for long-distance nonlinear fiber distortion compensation, using only the photodiode nonlinearity in an optical readout delivers BER improvements over three orders of magnitude. Combined with the amplifier saturation nonlinearity, we obtain another three orders of magnitude improvement of the BER.

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Third‐order optical nonlinearity and all‐optical switching in porous silicon

Applied Physics Letters ◽

10.1063/1.115432 ◽

1995 ◽

Vol 67 (3) ◽

pp. 323-325 ◽

Cited By ~ 88

Author(s):

Fryad Z. Henari ◽

Kai Morgenstern ◽

Werner J. Blau ◽

Vladimir A. Karavanskii ◽

Vladimir S. Dneprovskii

Keyword(s):

Porous Silicon ◽

Optical Switching ◽

Optical Nonlinearity ◽

Third Order ◽

All Optical ◽

All Optical Switching

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Ultrafast sub–30-fs all-optical switching based on gallium phosphide

Science Advances ◽

10.1126/sciadv.aaw3262 ◽

2019 ◽

Vol 5 (6) ◽

pp. eaaw3262 ◽

Cited By ~ 10

Author(s):

Gustavo Grinblat ◽

Michael P. Nielsen ◽

Paul Dichtl ◽

Yi Li ◽

Rupert F. Oulton ◽

...

Keyword(s):

Gallium Phosphide ◽

Optical Switching ◽

Near Infrared ◽

Optical Nonlinearity ◽

Photon Absorption ◽

Linear Absorption ◽

Two Photon Absorption ◽

Two Photon ◽

All Optical ◽

All Optical Switching

Gallium phosphide (GaP) is one of the few available materials with strong optical nonlinearity and negligible losses in the visible (λ > 450 nm) and near-infrared regime. In this work, we demonstrate that a GaP film can generate sub–30-fs (full width at half maximum) transmission modulation of up to ~70% in the 600- to 1000-nm wavelength range. Nonlinear simulations using parameters measured by theZ-scan approach indicate that the transmission modulation arises from the optical Kerr effect and two-photon absorption. Because of the absence of linear absorption, no slower free-carrier contribution is detected. These findings place GaP as a promising ultrafast material for all-optical switching at modulation speeds of up to 20 THz.

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All-optical long-distance soliton-based transmission systems

Optical Solitons ◽

10.1017/cbo9780511524189.004 ◽

1992 ◽

pp. 61-72

Author(s):

K. Smith ◽

L. F. Mollenauer

Keyword(s):

Long Distance ◽

Transmission Systems ◽

All Optical

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Three-input majority function with nonlinear material in all-optical domain

Journal of Optics ◽

10.1007/s12596-013-0137-x ◽

2013 ◽

Vol 42 (4) ◽

pp. 349-354 ◽

Cited By ~ 3

Author(s):

L. A.Bakhtiar ◽

E. Yaghoubi ◽

A. Adami ◽

S. M. Hamidi ◽

M. Hosseinzadeh

Keyword(s):

Nonlinear Material ◽

Majority Function ◽

All Optical ◽

Optical Domain

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Off-Resonance Control and All-Optical Switching: Expanded Dimensions in Nonlinear Optics

Applied Sciences ◽

10.3390/app9204252 ◽

2019 ◽

Vol 9 (20) ◽

pp. 4252 ◽

Cited By ~ 4

Author(s):

David S. Bradshaw ◽

Kayn A. Forbes ◽

David L. Andrews

Keyword(s):

Optical Switching ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Nonlinear Effects ◽

Optical Nonlinearity ◽

Moderate Intensity ◽

Linear Absorption ◽

Simultaneous Application ◽

All Optical ◽

All Optical Switching

The theory of non-resonant optical processes with intrinsic optical nonlinearity, such as harmonic generation, has been widely understood since the advent of the laser. In general, such effects involve multiphoton interactions that change the population of each input optical mode or modes. However, nonlinear effects can also arise through the input of an off-resonant laser beam that itself emerges unchanged. Many such effects have been largely overlooked. Using a quantum electrodynamical framework, this review provides detail on such optically nonlinear mechanisms that allow for a controlled increase or decrease in the intensity of linear absorption and fluorescence and in the efficiency of resonance energy transfer. The rate modifications responsible for these effects were achieved by the simultaneous application of an off-resonant beam with a moderate intensity, acting in a sense as an optical catalyst, conferring a new dimension of optical nonlinearity upon photoactive materials. It is shown that, in certain configurations, these mechanisms provide the basis for all-optical switching, i.e., the control of light-by-light, including an optical transistor scheme. The conclusion outlines other recently proposed all-optical switching systems.

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Comparison of Sagnac and Mach–Zehnder ultrafast all-optical interferometric switches based on a semiconductor resonant optical nonlinearity

Applied Optics ◽

10.1364/ao.35.000417 ◽

1996 ◽

Vol 35 (3) ◽

pp. 417 ◽

Cited By ~ 64

Author(s):

K. I. Kang ◽

T. G. Chang ◽

I. Glesk ◽

P. R. Prucnal

Keyword(s):

Optical Nonlinearity ◽

All Optical

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Large enhancement of optical nonlinearity using quantum dots embedded in a photonic crystal structure for all-optical switch applications

LEOS 2000. 2000 IEEE Annual Meeting Conference Proceedings. 13th Annual Meeting. IEEE Lasers and Electro-Optics Society 2000 Annual Meeting (Cat. No.00CH37080) ◽

10.1109/leos.2000.893927 ◽

2002 ◽

Author(s):

H. Nakamura ◽

S. Kohmoto ◽

N. Carlsson ◽

Y. Sugimoto ◽

K. Asakawa

Keyword(s):

Crystal Structure ◽

Quantum Dots ◽

Photonic Crystal ◽

Optical Switch ◽

Optical Nonlinearity ◽

Photonic Crystal Structure ◽

All Optical ◽

Large Enhancement ◽

All Optical Switch

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Implementation of All-Optical 1x4 Memory Register Unit using the Micro-Ring Resonator Structures

10.21203/rs.3.rs-300547/v1 ◽

2021 ◽

Author(s):

Ajay Kumar ◽

Manish Kumar ◽

Sumit Kumar Jindal ◽

Sanjeev Kumar Raghuwanshi ◽

Rakesh Choudhary

Keyword(s):

Electromagnetic Interference ◽

High Speed ◽

Ring Resonator ◽

Extinction Ratio ◽

Contrast Ratio ◽

Switching Activity ◽

Flip Flop ◽

Memory Register ◽

All Optical ◽

Optical Domain

Abstract Implementation of switching activity in the all-optical domain is one of the most important aspects in the field of modern high-speed and secured communication technology. Micro-ring Resonator (MRR) based switching activity can be used to implement all-optical active low tri-state buffer logic and clocked D flip-flop. The paper describes the switching activity of micro-ring resonator structures and the switching activity is further used to implement the effective all-optical 4 - bit memory register using the appropriate arrangement of all-optical tri-state buffers and clocked D flip-flops with the functionality of RD and WR. The complete description of layouts and switching mechanisms of all-optical 4-bit memory registers have been explained and appropriate MATLAB simulation results are presented to observe the suitability of the proposed unit. The analysis shows that implementation of tri-state buffer logic and D flip-flop assisted 4-bit memory register in the all-optical domain includes the considerable advantages of optical communication e.g. immunity to electromagnetic interference, parallel computing, compactness, signal security, etc. The manuscript describes the detailed analysis of performance parameters e. g. extinction ratio, contrast ratio, amplitude modulation, on-off ratio, and switching speed of micro-ring resonator structures to achieve an efficient selection of device parameters and finally describes an efficient technique to implement all-optical MRR based 1 x 4 memory registers.

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All-Optical Switching of an Epsilon-Near-Zero Plasmon in ITO

10.21203/rs.3.rs-40947/v1 ◽

2020 ◽

Author(s):

Justus Bohn ◽

Ting-Shan Luk ◽

Craig Tollerton ◽

Sam Hutchins ◽

Igal Brener ◽

...

Keyword(s):

Plasmon Resonance ◽

Indium Tin Oxide ◽

Optical Switching ◽

Pump Intensity ◽

Optical Nonlinearity ◽

Pump And Probe ◽

Plasmon Frequency ◽

All Optical ◽

All Optical Switching ◽

Epsilon Near Zero

Abstract Nonlinear optical devices and their implementation into modern nanophotonic architectures are constrained by their usually moderate nonlinear response. Recently, epsilon-near-zero (ENZ) materials have been found to have a strong optical nonlinearity, which can be enhanced through the use of cavities or nano-structuring. Here, we study the pump dependent properties of the plasmon resonance in the ENZ region in a thin layer of thin indium tin oxide (ITO). Exciting this mode using the Kretschmann-Raether configuration, we study reflection switching properties of a 60nm layer close to the resonant plasmon frequency. We demonstrate the thermal switching mechanism, which results in a shift in the plasmon resonance frequency of 20THz for a TM pump intensity of 75GW/cm2. For degenerate pump and probe frequencies, we highlight an additional coherent contribution, not previously isolated in ENZ nonlinear optics studies, which leads to an overall pump induced change in reflection from 1% to 45%.

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