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26. High-sensitive and disposable myocardial infarction biomarker immunosensor with optofluidic microtubule lasing

Author

Niu Panpan, Jiang Junfeng, Liu Kun, Wang Shuang, Wang Tong, Liu Yize, Zhang Xuezhi, Ding Zhenyang, and Liu Tiegen

Subjects
biomarker, cardiac troponin, immunosensor, optofluidic, whispering gallery mode, Physics, QC1-999
Abstract

The early diagnosis of myocardial infarction can significantly improve the survival rate in emergency treatment, which is mainly implemented by the immunoassay for myocardial infarction biomarkers such as cardiac troponins in blood. In this work, a disposable optofluidic microtubule whispering gallery mode (WGM) immunosensor for label-free cardiac troponin I-C (cTnI-C) complex detection has been proposed and demonstrated with active interrogation enhancement. The disposable microtubule is simply fabricated by a silica capillary with pressurized tapering technology for thin-wall, and the cTnI antibodies are immobilized on the inner wall surface of the microtubule through the self-adherent polydopamine substrate. By configuring the two coupling microfibers, the double-fiber-coupled microtubule cavity can serve as a tunable filter for the mutual-coupled polarimetric fiber ring laser (FRL), whose output laser wavelength is determined by the cTnI-C concentration in the optofluidic microtubule with inherent microfluidic channel. Due to the cyclic-cumulative gain of the FRL, the characteristic resonant peak of optical sensing signal is enhanced in the spectral width compression and the optical signal-to-noise ratio improvement, and therefore the optical immunosensor for cTnI-C can be achieved by tracking the output laser wavelength of the FRL conveniently. The dynamic binding and unbinding process of cTnI-C antigen–antibody is illustrated by monitoring the lasing peak wavelength continuously. Our all-fiber immunosensor demonstrated here has the advantages of fast label-free detection, real-time monitor, high sensitivity and disposable sensing element, which can be an innovative detecting tool in early diagnosis of myocardial infarction.

Published
2022
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32. 3D Optical Wedge and Movable Optical Axis LC Lens.

Author

Wu, Qi, Zhang, Hongxia, Jia, Dagong, and Liu, Tiegen

Subjects
BEAM steering, LIQUID crystals, FOCAL length, MECHANICAL movements, ELECTRODES
Abstract

Current liquid crystal (LC) lenses cannot achieve lossless arbitrary movement of the optical axis without mechanical movement. This article designs a novel bottom electrode through simulation and optimization, which forms a special LC lens with an Archimedean spiral electrode, realizing a 3D LC wedge and an arbitrarily movable LC lens. When only the bottom electrode is controlled, it achieves a maximum beam steering angle of 0.164°, which is nearly an order of magnitude larger than the current design. When the top and bottom electrodes are controlled jointly, a 0.164° movement of the lens optical axis is achieved. With focal length varies, the movement of the optical axis ranges from zero to infinity, and the lens surface remains unchanged during movement. The focus can move in a 3D conical area. When the thickness of the LC layer is 30 μm, the fastest response time reaches only 0.635 s, much faster than now. [ABSTRACT FROM AUTHOR]

Published
2024
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33. Nanomembrane blazed grating coupler for vertical fiber-chip interface.

Author

Liu, Xingyu, Guo, Rongxiang, Zhang, Shujiao, Zhang, Zunyue, Wang, Jiaqi, Liu, Tiegen, and Cheng, Zhenzhou

Subjects
ENGINEERING standards, STRUCTURAL engineering, OPTICAL communications, INTEGRATED circuits, MASS production
Abstract

Mid-infrared (mid-IR) silicon photonics holds promising applications for the Internet of Things, LiDAR, and optical communications. Perfectly vertical grating couplers are superior mid-IR light coupling techniques, featuring ease of packaging, positioning flexibility, and mass production scalability. However, high-efficiency mid-IR perfectly vertical grating couplers still need to be developed due to the difficulties of efficiently engineering grating directionality and diffracted light at long wavelengths. In this paper, we present a mid-IR nanomembrane blazed grating coupler with segmented structure engineering based on a standard multi-project wafer service. The method is based on exploring the improvement of the grating directionality and modal overlap by combining grating units with different structures and thicknesses. Experimental results showcase a maximum coupling efficiency of −4.4 dB with a 3-dB bandwidth of ∼70 nm at 2100 nm wavelengths. This study contributes to the strategy of designing exceptional grating couplers with multiple functional units, paving the way for developing mid-IR photonic integrated circuits based on silicon photonics foundries. [ABSTRACT FROM AUTHOR]

Published
2024
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35. High-Q silicon microring resonator with ultrathin sub-wavelength thicknesses for sensitive gas sensing

Author

Guo, Rongxiang, primary, He, Qi, additional, Zhang, Zunyue, additional, Xu, Yingqi, additional, Zhang, Shujiao, additional, Lang, Qiyue, additional, Xiao, Shuqi, additional, Han, Peize, additional, Wang, Jiaqi, additional, Ding, Tianben, additional, Liu, Tiegen, additional, Tsang, Hon Ki, additional, Goda, Keisuke, additional, and Cheng, Zhenzhou, additional

Published
2024
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40. Analytical Investigations on Carrier Phase Recovery in Dispersion-Unmanaged n-PSK Coherent Optical Communication Systems

Author

Xu, Tianhua, Jacobsen, Gunnar, Popov, Sergei, Li, Jie, Liu, Tiegen, Zhang, Yimo, and Bayvel, Polina

Subjects
Computer Science - Information Theory, 94A12, C.2.5
Abstract

Using coherent optical detection and digital signal processing, laser phase noise and equalization enhanced phase noise can be effectively mitigated using the feed-forward and feed-back carrier phase recovery approaches. In this paper, theoretical analyses of feed-back and feed-forward carrier phase recovery methods have been carried out in the long-haul high-speed n-level phase shift keying (n-PSK) optical fiber communication systems, involving a one-tap normalized least-mean-square (LMS) algorithm, a block-wise average algorithm, and a Viterbi-Viterbi algorithm. The analytical expressions for evaluating the estimated carrier phase and for predicting the bit-error-rate (BER) performance (such as the BER floors) have been presented and discussed in the n-PSK coherent optical transmission systems by considering both the laser phase noise and the equalization enhanced phase noise. The results indicate that the Viterbi-Viterbi carrier phase recovery algorithm outperforms the one-tap normalized LMS and the block-wise average algorithms for small phase noise variance (or effective phase noise variance), while the one-tap normalized LMS algorithm shows a better performance than the other two algorithms for large phase noise variance (or effective phase noise variance). In addition, the one-tap normalized LMS algorithm is more sensitive to the level of modulation formats.

Published
2016

41. Analytical Estimation in Differential Optical Transmission Systems Influenced by Equalization Enhanced Phase Noise

Author

Xu, Tianhua, Jacobsen, Gunnar, Popov, Sergei, Liu, Tiegen, Zhang, Yimo, and Bayvel, Polina

Subjects
Computer Science - Information Theory, 94A05, C.2.5
Abstract

An analytical model is presented for assessing the performance of the bit-error-rate (BER) in the differential m-level phase shift keying (m-PSK) transmission systems, where the influence of equalization enhanced phase noise (EEPN) has been considered. Theoretical analysis has been carried out in differential quadrature phase shift keying (DQPSK), differential 8-PSK (D8PSK), and differential 16-PSK (D16PSK) coherent optical transmission systems. The influence of EEPN on the BER performance, in term of signal-to-noise ratio (SNR), are investigated for different fiber dispersion, LO laser linewidths, symbol rates, and modulation formats. Our analytical model achieves a good agreement with previously reported EEPN induced BER floors, and can give an accurate prediction for the DQPSK system, and a leading-order approximation for the D8PSK and the D16PSK systems., Comment: Progress in Electromagnetics Research Symposium (PIERS) 2016

Published
2016

42. Analysis of chromatic dispersion compensation and carrier phase recovery in long-haul optical transmission system influenced by equalization enhanced phase noise

Author

Xu, Tianhua, Jacobsen, Gunnar, Popov, Sergei, Li, Jie, Sergeyev, Sergey, Friberg, Ari T., Liu, Tiegen, and Zhang, Yimo

Subjects
Computer Science - Information Theory, Physics - Optics, 94A12, C.2.5
Abstract

The performance of long-haul coherent optical fiber transmission system is significantly affected by the equalization enhanced phase noise (EEPN), due to the interaction between the electronic dispersion compensation (EDC) and the laser phase noise. In this paper, we present a comprehensive study on different chromatic dispersion (CD) compensation and carrier phase recovery (CPR) approaches, in the n-level phase shift keying (n-PSK) and the n-level quadrature amplitude modulation (n-QAM) coherent optical transmission systems, considering the impacts of EEPN. Four CD compensation methods are considered: the time-domain equalization (TDE), the frequency-domain equalization (FDE), the least mean square (LMS) adaptive equalization are applied for EDC, and the dispersion compensating fiber (DCF) is employed for optical dispersion compensation (ODC). Meanwhile, three carrier phase recovery methods are also involved: a one-tap normalized least mean square (NLMS) algorithm, a block-wise average (BWA) algorithm, and a Viterbi-Viterbi (VV) algorithm. Numerical simulations have been carried out in a 28-Gbaud dual-polarization quadrature phase shift keying (DP-QPSK) coherent transmission system, and the results indicate that the origin of EEPN depends on the choice of chromatic dispersion compensation methods, and the effects of EEPN also behave moderately different in accordance to different carrier phase recovery scenarios.

Published
2016
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43. Digital Adaptive Carrier Phase Estimation in Multi-Level Phase Shift Keying Coherent Optical Communication Systems

Author

Xu, Tianhua, Liu, Tiegen, Zhang, Yimo, Jacobsen, Gunnar, Li, Jie, and Popov, Sergei

Subjects
Computer Science - Information Theory, 94A12, C.2.5
Abstract

The analysis of adaptive carrier phase estimation is investigated in long-haul high speed n-level phase shift keying (n-PSK) optical fiber communication systems based on the one-tap normalized least-mean-square (LMS) algorithm. The close-form expressions for the estimated carrier phase and the bit-error-rate floor have been derived in the n-PSK coherent optical transmission systems. The results show that the one-tap normalized LMS algorithm performs pretty well in the carrier phase estimation, but will be less effective with the increment of modulation levels, in the compensation of both intrinsic laser phase noise and equalization enhanced phase noise., Comment: 5 pages in [IEEE] International Conference on Information Science and Control Engineering (ICISCE) 2016. arXiv admin note: text overlap with arXiv:1602.06850

Published
2016
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44. Carrier Phase Estimation in Dispersion-Unmanaged Optical Transmission Systems

Author

Xu, Tianhua, Bayvel, Polina, Liu, Tiegen, Zhang, Yimo, Jacobsen, Gunnar, Li, Jie, and Popov, Sergei

Subjects
Computer Science - Information Theory, Physics - Classical Physics, Physics - Optics, 94A12, C.2.5
Abstract

The study on carrier phase estimation (CPE) approaches, involving a one-tap normalized least-mean-square (NLMS) algorithm, a block-wise average algorithm, and a Viterbi-Viterbi algorithm has been carried out in the long-haul high-capacity dispersion-unmanaged coherent optical systems. The close-form expressions and analytical predictions for bit-error-rate behaviors in these CPE methods have been analyzed by considering both the laser phase noise and the equalization enhanced phase noise. It is found that the Viterbi-Viterbi algorithm outperforms the one-tap NLMS and the block-wise average algorithms for a small phase noise variance (or effective phase noise variance), while the three CPE methods converge to a similar performance for a large phase noise variance (or effective phase noise variance). In addition, the differences between the three CPE approaches become smaller for higher-level modulation formats.

Published
2016

45. Close-Form Expression of One-Tap Normalized LMS Carrier Phase Recovery in Optical Communication Systems

Author

Xu, Tianhua, Jacobsen, Gunnar, Popov, Sergei, Li, Jie, Liu, Tiegen, and Zhang, Yimo

Subjects
Physics - Optics, Computer Science - Information Theory, 78A55, C.2.5
Abstract

The performance of long-haul high speed coherent optical fiber communication systems is significantly degraded by the laser phase noise and the equalization enhanced phase noise (EEPN). In this paper, the analysis of the one-tap normalized least-mean-square (LMS) carrier phase recovery (CPR) is carried out and the close-form expression is investigated for quadrature phase shift keying (QPSK) coherent optical fiber communication systems, in compensating both laser phase noise and equalization enhanced phase noise. Numerical simulations have also been implemented to verify the theoretical analysis. It is found that the one-tap normalized least-mean-square algorithm gives the same analytical expression for predicting CPR bit-error-rate (BER) floors as the traditional differential carrier phase recovery, when both the laser phase noise and the equalization enhanced phase noise are taken into account., Comment: [SPIE] International Conference on Wireless and Optical Communications (ICWOC) 2016, W22

Published
2016
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46. Integrated optoelectronics with two-dimensional materials

Author

Cheng Zhenzhou, Guo Rongxiang, Wang Jiaqi, Wang Yi, Xing Zhengkun, Ma Lei, Wei Wei, Yu Yu, Tsang Hon Ki, and Liu Tiegen

Subjects
integrated optoelectronics, two-dimensional materials, heterogeneous integration, silicon photonics, Science, Engineering (General). Civil engineering (General), TA1-2040
Abstract

As we enter the post-Moore era, heterogeneous optoelectronic integrated circuits (OEICs) are attracting significant attention as an alternative approach to scaling to smaller-sized transistors. Two-dimensional (2D) materials, offering a range of intriguing optoelectronic properties as semiconductors, semimetals, and insulators, provide great potential for developing next-generation heterogeneous OEICs. For instance, Fermi levels of 2D materials can be tuned by applying electrical voltages, while their atomically thin geometries are inherently suited for the fabrication of planar devices without suffering from lattice mismatch. Since the first graphene-on-silicon OEICs were demonstrated in 2011, 2D-material heterogeneous OEICs have significantly progressed. To date, researchers have a better understanding of the importance of interface states on the optical properties of chip-integrated 2D materials. Moreover, there has been impressive progress towards the use of 2D materials for waveguide-integrated lasers, modulators, and photodetectors. In this review, we summarize the history, status, and trend of integrated optoelectronics with 2D materials.

Published
2022
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