1,720,971 research outputs found
Dataset for the publication: 'Monolithically integrated polarization rotator and splitter with designed power ratio'
No full textThis dataset contains the raw data for the figures in the publication titled "Monolithically integrated polarization rotator and splitter with designed power ratio" in Optics Express. Datafiles are in .xlsx format.</span
Dataset supporting the publication:Optical mode localization sensing based on fibre-coupled ring resonators
No full textThis dataset contains the raw data for the figures in the publication titled "Optical mode localization sensing based on fibre-coupled ring resonators" in Optics Express. Datafiles are in .xlsx format.</span
Photonic integrated circuit: Optimization and applications.
No full textPhotonic integrated circuit (PIC) is a device that combines multiple optical components on a single silicon chip. It leverages the properties of silicon to enable the integration of complex optical functionalities. PIC offers several advantages, including high integration density, compatibility with CMOS fabrication process, low power consumption and potential for large-scale production. They have applications in various fields such as data communication, sensing, nonlinear optics, quantum optics, etc. This thesis proposes three novel PICs that can be applied to different fields including nonlinear optics and sensing, respectively. Firstly, an unsuspended silicon waveguide platform for enhanced stimulated Brillouin scattering is proposed. The structure is optimized by using genetic algorithm (GA). By limiting the maximum etching step to two during the GA process, a simple and fabricable unsuspended structure is obtained. The optimized platform can realize large SBS gain without suspending the Si waveguide. The best gain coefficient comes from the forward SBS of fundamental TE-like mode with the value of 2462W−1m−1. This gain value is 8 times larger than the recent result. Secondly, a novel on-chip optical frequency domain reflectometry (OFDR) system is proposed theoretically and experimentally. The experiment results show that the system achieves a spatial resolution of 7.59μm, which is, to our best knowledge, the highest value achieved on-chip. The optical components in the system are designed by traditional methods and photonic inverse design approach, respectively. It is found that the footprint of the inverse-designed-components is at least 20 times smaller than the devices designed by traditional methods, which is essential for ultra-compact PIC. In addition, to further improve the detecting scheme of the on-chip OFDR system, a modified direct-binary-search (DBS) algorithm is proposed and used to design a novel monolithically integrated polarization rotator and splitter with designed power ratio. The device can fulfil both polarization rotation (TE00 to TE00 and TM00 modes) and power splitting with a designed power ratio. The measured insertion loss is less than 1 dB and the crosstalk between TE00 and TM00 modes is less than -9.5 dB. This device iv can improve the detecting scheme of our on-chip OFDR system, where the detection complexity of the system can be reduced. Lastly, mode localization is, for the first time, established in optical system. A novel sensing mechanism based on the optical mode localization effect is applied to both optical fibre system and PIC to form ultra-sensitive sensors, respectively. The experiment results exhibit at least 3 orders of magnitudes higher sensitivity than the traditional frequency-shift, which can be applied for ultra-sensitive temperature sensing and high-speed modulation
Monolithically integrated polarization rotator and splitter with designed power ratio
No full textInverse designs are widely used for creating ultra-compact photonic devices, but suffer from high computation power due to the optimization complexity. General Stoke’s theorem proves that the overall change present at the outer boundary is equal to the integral of the change over the inner intervals, providing the possibility to divide one sophisticated device into several simple building blocks. Thus, we integrate this theorem with the inverse designs as a novel design methodology for optical devices. Compared with conventional inverse designs, the separated regional-optimisations can reduce the computational complexity significantly. The overall computational time is around five times shorter than optimizing the whole device region. To validate the proposed methodology, a monolithically integrated polarization rotator and splitter is designed and fabricated to demonstrate the performance experimentally. The device achieves polarization rotation (TE
00 to TE
00 and TM
00 modes) and power splitting with the designed power ratio. The exhibited average insertion loss is <1 dB and the crosstalk is <-9.5 dB. These findings confirm the advantages of the new design methodology, as well as its feasibility for achieving multiple functions on one monolithic device.
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Dataset in support of the paper 'Optical mode localized sensing in on-chip coupled microring resonators'
No full textThis dataset provides the data for plotting Fig. 2b, Fig.3, Fig. 4, Fig. 5 and Fig. 6 in the paper (Title: Optical mode localized sensing in on-chip coupled microring resonators) published in journal Optics Express.</span
Theory analysis of the optical mode localized sensing based on coupled ring resonators
No full textBased on Mason's signal flow graph analysis, an analytical model of the optical mode localization based on coupled ring resonators is established. The correctness of the theoretical model is proved by simulation. High sensitivity and common-mode rejection can be achieved by evaluating the modal power ratio from resonant peaks as sensing output. Based on the four-port structure, two output spectrum with mode localization (asymmetric mode splitting) and symmetric mode splitting allows the high-sensitivity sensing and dual-channel calibration to be carried out simultaneously, which can reduce the sensing errors. Monte-Carlo analysis showed that fabrication imperfection changes less than 6% of the performance in 90% cases, thus the construction of practical sensors is possible with appropriate tuning. The optical mode localized sensing has advantages in sensitivity, accuracy, anti-aliasing compared with conventional micro-mechanical mode localized sensor. Various types of high-sensitive sensor can be constructed through coupling parametric perturbation with measurands in different physical domains
Optical mode localization sensing based on fiber-coupled ring resonators
No full textMode localization is widely used in coupled micro-electro-mechanical system (MEMS) resonators for ultra-sensitive sensing. Here, for the first time to the best of our knowledge, we experimentally demonstrate the phenomenon of optical mode localization in fiber-coupled ring resonators. For an optical system, resonant mode splitting happens when multiple resonators are coupled. Localized external perturbation applied to the system will cause uneven energy distributions of the split modes to the coupled rings, this phenomenon is called the optical mode localization. In this paper, two fiber-ring resonators are coupled. The perturbation is generated by two thermoelectric heaters. We define the normalized amplitude difference between the two split modes as: (T
M1 − T
M
2)/T
M
1 × 100%. It is found that this value can be varied from 2.5% to 22.5% when the temperature are changed by the value from 0K to 8.5K. This brings a ∼ 2.4%/K variation rate, which is three orders of magnitude greater than the variation rate of the frequency over temperature changes of the resonator due to thermal perturbation. The measured data reach good agreement with theoretical results, which demonstrates the feasibility of optical mode localization as a new sensing mechanism for ultra-sensitive fiber temperature sensing.
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Dataset supporting the publication: Enhanced stimulated brillouin scattering in unsuspended silicon waveguide assisted with genetic algorithms.
No full textThis dataset contains the raw data for the figures in the publication titled "Enhanced stimulated brillouin scattering in unsuspended silicon waveguide assisted with genetic algorithms" in Optics Express. Datafiles are in .xlsx format.</span
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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