Bandwidth Tunable Optical Bandpass Filter Based on Parity-Time Symmetry

A chip-scale tunable optical filter is indispensable to meeting the demand for reconfigurability in wavelength division multiplexing systems, channel routing, and switching, etc. Here, we propose a new scheme of bandwidth tunable band-pass filters based on a parity-time (PT) symmetric coupled microresonator system. Large bandwidth tunability is realized on the basis of the tuning of the relative resonant frequency between coupled rings and by making use of the concept of the exception point (EP) in the PT symmetric systems. Theoretical investigations show that the bandwidth tuning range depends on the intrinsic loss of the microresonators, as well as on the loss contrast between the two cavities. Our proof-of-concept device confirms the tunability and shows a bandwidth tuning range from 21 GHz to 49 GHz, with an extinction ratio larger than 15 dB. The discrepancy between theory and experiment is due to the non-optimized design of the coupling coefficients, as well as to fabrication errors. Our design based on PT symmetry shows a distinct route towards the realization of tunable band-pass filters, providing new ways to explore non-Hermitian light manipulation in conventional integrated devices.

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Analysis of gallium nitride-based optical microring resonator with doped polymer grafting material

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v24.i2.pp736-743 ◽

2021 ◽

Vol 24 (2) ◽

pp. 736

Author(s):

Hazura Haroon ◽

Muhammad Syafiq Ramli ◽

Siti Khadijah Idris ◽

Anis Suhaila Mohd Zain ◽

Hanim Abdul Razak ◽

...

Keyword(s):

Gallium Nitride ◽

Wavelength Division Multiplexing ◽

Extinction Ratio ◽

Microring Resonator ◽

Design Parameters ◽

Optimized Design ◽

Extinction Rate ◽

Polymer Grafting ◽

Wavelength Division ◽

Waveguide Width

<p>In this paper, the Gallium nitride-based optical microring resonator (OMR) filter with polymer grafting material (PMMA) coating was designed and optimized to predict its potential as a wavelength filtering device. The optimization was focused on the design parameters such as polymer thickness, gap separation variation, and the bus and ring waveguide widths. The target is to achieve the best output in terms of insertion loss (IL) and Extinction Ratio for wavelength-division multiplexing (WDM) applications, specifically for the use of the C-Band network. Upon completion, it was found that the optimized design was a ring radius of 10 μm and PMMA thickness of 0.055 μm, with the bus waveguide width of 800 nm and the output bus waveguide of 800 nm giving the observed IL of 0.07 dB and 87.3% extinction rate.</p>

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Systematic identification of crosstalk and bandwidth upper limit in highly cascaded Mach-Zehnder lattice optical filters

Japanese Journal of Applied Physics ◽

10.35848/1347-4065/ac43ce ◽

2021 ◽

Author(s):

Jun Ushida ◽

Tadashi Murao ◽

Akemi Shiina ◽

Tsuyoshi Horikawa

Keyword(s):

Wavelength Division Multiplexing ◽

Communication Systems ◽

Direct Detection ◽

Optical Filter ◽

Optical Filters ◽

Coupling Coefficients ◽

Wafer Level ◽

Wavelength Division ◽

Level Measurement ◽

Upper Limit

Abstract Crosstalk among channels in wavelength division multiplexing (WDM) filters must be suppressed to enhance receiver sensitivity in direct-detection-based optical communication systems. We present a systematic method to identify the maximum crosstalk and upper limit of the transmission spectrum bandwidth of a highly multi-staged Mach-Zehnder interference (MZI) lattice optical filter with a number of cascade N (N=1,2,…,∞). The scattering matrix including the wafer-level-measurement-based coupling coefficients of directional couplers is used to calculate the transmittance from the input to each output channel and the result is exactly extrapolated to infinite N. This method can be used to design, characterize, and evaluate $N$-cascaded MZI lattice optical filters that must meet strict WDM specifications.

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A Switchable Optical Filter between Band-stop and Band-pass Responses

2020 Opto-Electronics and Communications Conference (OECC) ◽

10.1109/oecc48412.2020.9273709 ◽

2020 ◽

Author(s):

Weijun Jiang ◽

Lu Xu ◽

Xiaolong Liu ◽

Yu Yu ◽

Yuan Yu ◽

...

Keyword(s):

Optical Filter ◽

Band Pass

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Comparative Analysis of Erbium Doped Fiber Amplifier (EDFA) and Raman Optical Amplifier (ROA) in Nonlinear-CWDM System

JURNAL INFOTEL ◽

10.20895/infotel.v10i3.378 ◽

2018 ◽

Vol 10 (3) ◽

pp. 144

Author(s):

Dodi Zulherman ◽

Sri Utami ◽

Fahmi Fahmi

Keyword(s):

Wavelength Division Multiplexing ◽

System Performance ◽

Fiber Amplifier ◽

Optical Amplifier ◽

High Rate ◽

Telecommunication Service ◽

Raman Amplification ◽

Erbium Doped Fiber Amplifier ◽

Large Bandwidth ◽

Erbium Doped

The massive demands for high-rate application drove the telecommunication service to use large bandwidth capacity. The Coarse Wavelength Division Multiplexing (CWDM), a common use in Metro-WDM, can be a solution to provide large bandwidth in optical communications. In a communications system, there are attenuation and nonlinear effect decreasing the system performance. In order to overcome the limitation imposed by electrical regeneration to maintain system performance, a means of optical amplification was sought. In this paper presents the comparison of two competing technologies emerged: Erbium Doped Fiber Amplifier (EDFA) and Raman Optical Amplifier (ROA) to overcome the attenuation in the nonlinear system. We designed the CWDM system using 8 channels with 20 nm channel spacing and 60 km length. The result was conducted by varying the CW Laser power using -8, -6, -4, -2, 0, 2, 4, and 6 dBm. Based on the result of the research, raman amplification can maintain the BER and the Q-factor of the CWDM system better than EDFA. In addition, the received power in raman amplification larger than that received in EDFA. In conclusion,a CWDM system using ROA amplifier has better performance for the system than using EDFA amplifier.

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A Reconfigurable Radio-Frequency Converter IC in 0.18 µm CMOS

Electronics ◽

10.3390/electronics8101146 ◽

2019 ◽

Vol 8 (10) ◽

pp. 1146

Author(s):

Carlos Sánchez-Azqueta ◽

Erick Guerrero ◽

Cecilia Gimeno ◽

Santiago Celma

Keyword(s):

Wavelength Division Multiplexing ◽

Frequency Synthesizer ◽

Frequency Converter ◽

Impedance Matching ◽

Cmos Process ◽

Wavelength Division ◽

Triple Play ◽

Band Pass ◽

Reconfigurable Radio ◽

Lc Tank

This work presents a reconfigurable RF converter for DVB-T television applications using triple-play over GPON. The system takes the DVB-T input, a wavelength division multiplexing (WDM) signal with spectral inversion in the range from 47 M Hz –1000 M Hz , up-converts its frequency to the band-pass of a highly selective surface-acoustic wave (SAW) filter centered at 1 . 3 G Hz , and then down-converts it so that it is compatible with the antenna input of conventional television sets. The designed RF converter incorporates two pairs of frequency synthesizer and mixer, based, respectively, on an integer-N phase-locked loop (PLL) with two LC-tank VCOs with 128 coarse tuning bands in the range from 1.35 G Hz –2.7 G Hz , and a double-balanced Gilbert cell, modified for better impedance matching and improved linearity. It is fed with regulated supplies compensated in temperature and programmed by an I 2 C interface operating on five 16-bit registers. This work presents the experimental characterization of the whole system plus selected cells for stand-alone testing, which have been fabricated in a 0 . 18 m CMOS process.

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A MEMS-based all-dielectric tunable optical filter with increased tuning range

10.1117/12.545346 ◽

2004 ◽

Author(s):

Dennis Hohlfeld ◽

Hans Zappe

Keyword(s):

Tuning Range ◽

Optical Filter ◽

Tunable Optical Filter

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Network experiment using an 8000 GHz tuning-range optical filter

Electronics Letters ◽

10.1049/el:19880726 ◽

1988 ◽

Vol 24 (17) ◽

pp. 1071 ◽

Cited By ~ 12

Author(s):

A.R. Chraplyvy ◽

R.W. Tkach ◽

R.M. Derosier

Keyword(s):

Tuning Range ◽

Optical Filter ◽

Network Experiment

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Thermo-Optic Tunable Optical Filter Based on Fabry-Perot Microcavities in SOI

Advanced Engineering Forum ◽

10.4028/www.scientific.net/aef.6-7.194 ◽

2012 ◽

Vol 6-7 ◽

pp. 194-199

Author(s):

Zhe Li ◽

Hua Juan Qi ◽

Yong Chuan Xiao ◽

Feng Li Gao

Keyword(s):

Refractive Index ◽

Wavelength Division Multiplexing ◽

Optical Filter ◽

Silicon On Insulator ◽

Central Wavelength ◽

Wavelength Division ◽

Tunable Optical Filter ◽

Compact Size ◽

Fabry Perot ◽

Output Characteristics

An integrated TOF (Tunable Optical Filter) based on thermo-optic effect in Silicon on insulator (SOI) rib waveguide is designed and simulated. The device is comprised of two high refractivity contrast Si/Air stacks, functioning as high reflectivity of DBRs and separated by a variable refractive index Si F-P cavity. The output characteristics are calculated and simulated based on Transfer Matrix Method (TMM). Wavelength tuning is achieved through thermal modulation of refractive variation of the cavity.As the cavity Si is heated,the refractive index of the cavity increases.When the temperature of cavity Si changes within100°C，the central wavelength gets a continuous 8nm shift from 1550nm to 1558nm, which is right located in the WDM (Wavelength division multiplexing) networks operating at C-band. Moreover, by calculating, the tuning sensitivity is about 0.08nm/°C. Owing to the compact size and excellent characteristics of integration, the proposed component has a promising utilization in spectroscopy and optical communication.

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