In this paper, a cholesterol biosensor is developed using a single-mode fiber (SMF) and a hollow core fiber (HCF) to detect and measure the cholesterol concentration in the human body. The ...sensitivity of an SMF-HCF structure (sensor probe) has been enhanced by the localized surface plasmon resonance (LSPR) technique using the gold nanoparticles (AuNPs) of 11± 0.5 nm particle size. Furthermore, sensor probe was functionalized with cholesterol oxidase (ChOx) enzyme to increase the selectivity of biosensor. The synthesis of AuNPs is confirmed by a UV-visible spectrophotometer, transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy (EDS). Furthermore, the coating of AuNPs over an optical fiber is verified by scanning electron microscope (SEM). The linearity range and detection limit of the proposed sensor are 50 nM-<inline-formula> <tex-math notation="LaTeX">1~\mu \text{M} </tex-math></inline-formula> and 25.5 nM, respectively. The selectivity of biosensor has been determined with the 10-mM concentration of different solutions of cholesterol, glucose, urea, ascorbic acid, L-cysteine, and galactose that are generally present in serum.
We will present our recent work on the reliability of specialty optical fibers designed for use in silicon photonics, subjected to reflow soldering process conditions. Coating thermal stability, ...fiber mechanical properties, and induced optical loss after reflow soldering will be discussed. Performances of post-reflow fibers under temperature cycling and damp heat aging environmental tests will also be discussed.
As a new approach to realizing high-precision time synchronization between remote time scales, quantum two-way time transfer via laboratory fiber link has shown significant enhancement of the ...transfer stability to several tens of femtoseconds. To verify its great potential in practical systems, the field test in long-haul installed fiber optic infrastructure is required to be demonstrated. In this article, we implement the two-way quantum time transfer over a 103 km urban fiber link. A time transfer stability of 3.67 ps at 10 s and 0.28 ps at 40 000 s has been achieved, despite the large attenuation of 38 dB leading to fewer than 40 correlated events per second. This achievement marks the first successful step of quantum two-way time transfer in the task of high-precision long-distance field transfer systems.
The power scaling of single mode fiber lasers and amplifiers, due to the wide area of applications, has been the subject of great interest for many years. Increasing the mode area seems to be the ...obvious way to scale up the output power level from the single emitter if you consider well-known limitations like nonlinear effects, material damage threshold or thermal lensing. The nanostructurization of the fiber core is a method to control precisely optical properties of the active fiber. This method allows to design and develop the fiber with the core of any arbitrary defined refractive index distribution, with precision not available with other known fiber technology. The nanostructurization also open up an opportunity to incorporate simultaneously various active and non-active glasses into the fiber core. Those advantages can be used to fabricate the new class of fibers for laser applications. Here we show ytterbium doped phosphate single-mode fiber with nanostructured core, which is the first proof-of-concept of active fiber with entirely nanostructured core area.
The combination of multi-band optical transmission and ITU-T G.654 loss-minimized large-effective-area fibers enables superior network performance in the low-loss C+L wavelength bands. As the maximum ...cut-off wavelength of the G.654 fiber is increased to 1530 nm, from 1260 nm in the commonly used G.652 fiber, the multi-path interference (MPI) resulting from the interplay between the fundamental LP01 mode and the high-order LP11 mode needs to be considered when expanding the multi-band transmission window to cover the S+E+O bands. In this paper, we study optical layer impairments such as the LP01-LP11 mode coupling induced MPI in G.654 fiber, the negative impact of the stimulated Raman scattering (SRS) on the use of optical supervisory channel (OSC) and optical time domain reflectometer (OTDR) in all fiber types, and the four-wave-mixing (FWM) issue in the O-band transmission over G.652 fiber, and discuss the corresponding mitigation techniques. Extensive measurements of G.654.E fibers are made to evaluate the MPI. For impact of MPI, we include it, along with the nonlinear interference, in the generalized Gaussian noise model to accurately assess the link performance, and mitigation strategies are discussed. Additional considerations of diverse optical link conditions on amplification schemes, link distances, and cost constraints are made for provisioning C+L+S+E+O multi-band optical networks with the combined use of both G.652 and G.654 fibers, aiming for the optimal utilization of the multi-band transmission in future ultrahigh-capacity optical networks for a wide variety of applications.
To economically manage the rapid traffic growth in data center networks, transmission technologies need to be studied for next-generation high-speed Ethernet, such as 1.6 TbE and beyond. This article ...describes a demonstration of 1.6 Tb/s (4 × 400-Gb/s/lane) O-band transmission over 10 km of installed four-core fiber. Since chromatic dispersion limits the transmission distance of the high-speed intensity-modulated direct detection (IM-DD) signals, a space division multiplexed technology using the 10-km four-core fiber is suitable to parallelly transmit 400-Gb/s/lane signals at near-zero dispersion wavelengths. A net-rate of 400 Gb/s/lane IM-DD signals with 155-GBd pulse amplitude modulation-8 (PAM-8) is generated by using an in-house broadband amplifier based on an InP double hetero-junction bipolar transistor (InP-DHBT). Our nonlinear maximum likelihood sequence estimation (NL-MLSE) enhances the performance of the 400-Gb/s/lane signals. We also introduce a technique called trellis path-limitation MLSE (TL-MLSE) for reducing computational complexity with temporarily decided results and a truncated trellis diagram. The trellis path-limitation MLSE with nonlinear calculation function (TL-NL-MLSE) achieves 1.6-Tb/s 10-km transmission in the O-band with the same performance as and lower computational complexity than the NL-MLSE.
We present a symmetric physical layer based secret key generation scheme for Point-to-Point Optical Link (PPOL) communication by exploiting Polarization Mode Dispersion (PMD) as a random and ...inimitable channel characteristic. The randomness and security strength of generated cryptographic keys based on PMD is significantly high. In this paper, we present that random modulation of a probe signal caused by PMD in a high-speed data communication network (40 Gb/s and 60 Gb/s) is reciprocal with average Pearson correlation coefficient of 0.862, despite the presence of optical nonlinearities, dispersion, and noise in the system. 128-bit symmetric cryptographic key has been successfully generated using the proposed scheme. Moreover, PMD-based encryption keys passed the National Institute of Standards and Technology (NIST) tests. We have shown through simulations with a 50 km link that, with optimal key generation settings, symmetric keys can be generated with high randomness (high P-values for NIST randomness tests) and with sufficient generation rates (>50%). Furthermore, we considered an attack model of a non-invasive adversary intercepting at 10 km into the link and found that the generated keys have high average key bit mismatch rates (>40%).
High Power Fiber Lasers: A Review Zervas, Michalis N.; Codemard, Christophe A.
IEEE journal of selected topics in quantum electronics,
09/2014, Letnik:
20, Številka:
5
Journal Article
Recenzirano
In this paper, we summarize the fundamental properties and review the latest developments in high power fiber lasers. The review is focused primarily on the most common fiber laser configurations and ...the associated cladding pumping issues. Special attention is placed on pump combination techniques and the parameters that affect the brightness enhancement observed in single-mode and multimode high power fiber lasers. The review includes the major limitations imposed by fiber nonlinearities and other parasitic effects, such as optical damage, transverse modal instabilities and photodarkening. Finally, the paper summarizes the power evolution in continuous-wave and pulsed ytterbium-doped fiber lasers and their impact on industrial applications.
We investigate the relationship between the inter-core crosstalk (IC-XT) and polarization-mode dispersion (PMD) of multi-core fibers (MCFs) with differing cladding diameter ( d CL ). The study is ...based on the assumption that the IC-XT is primarily characterized by random coupling occurring between polarization-modes along the propagation process. Our investigation involved the analysis of two 2-core weakly-coupled heterogeneous MCFs, sharing almost identical cores but differing in d CL . Here, we introduce a method to estimate the birefringence parameters for each core, obtained from a combination of measured and numerically calculated data of IC-XT and PMD. Under the assumption that both cores have identical birefringence beat length L B values, the results reveal an opposite relationship between the IC-XT and PMD characteristics, where increasing the d CL results in an improvement of the IC-XT, but at the cost of the deterioration of the PMD. The same behavior was observed even when minor differences in L B between cores were considered. Moreover, our estimated values of the birefringence parameters for each fiber core are several orders of magnitude smaller than those reported in conventional single-mode fibers.
The transfer matrix is proposed to describe the coherent cross-polarization coupling (CPC) induced by a single point-like perturbation (PLP) in optical fibers. This matrix remains independent of the ...fiber length, making it suitable for characterizing the PLP that have a zero-dimensional impact on fiber length. Consequently, the fiber can be fully characterized by a matrix combining the transfer matrix of CPC and the Jones matrix of the fiber birefringence. The polarization performance of fibers exhibiting both CPC and birefringence is analyzed using the developed combined model.
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