The performance of a cost-effective optical comb source using commercial off the shelf (COTS) components in a WDM passive optical network is demonstrated. Eight comb modes are individually modulated at 10.7 Gb/s and transmitted over 50 km of single mode fiber for downlink transmission. Error free performance is obtained for each comb line and a maximum performance difference of 1.4 dB is experienced between the eight channels. Colorless operation of the optical network unit is achieved by utilizing an integrated module consisting of a tunable laser and an electro-absorption modulator as an uplink transmitter. Finally the predicted downstream performance of the system, when all the channels are transmitted simultaneously, is numerically simulated.
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http://dx.doi.org/10.1364/OE.18.015672 | DOI Listing |
Br J Ophthalmol
January 2025
Zanzibar Ministry of Health, Zanzibar, Mkoa wa Unguja Mjini Magh, United Republic of Tanzania.
Background: A pilot eyecare programme aimed to address the urgent eye health needs of older Zanzibari craftswomen. We investigated the impact of correcting presbyopia on their subjective well-being (SWB) 6 months post-correction and assessed the cost-effectiveness of a women-targeted presbyopia correction programme.
Methods: This study involved Zanzibari craftswomen aged 40 and older with presenting and corrected distance visual acuity better than 6/12 in both eyes and were presbyopic.
Appl Neuropsychol Adult
January 2025
Faculty Xavier Institute of Engineering, Mahim, India.
In the fields of engineering, science, technology, and medicine, artificial intelligence (AI) has made significant advancements. In particular, the application of AI techniques in medicine, such as machine learning (ML) and deep learning (DL), is rapidly growing and offers great potential for aiding physicians in the early diagnosis of illnesses. Depression, one of the most prevalent and debilitating mental illnesses, is projected to become the leading cause of disability worldwide by 2040.
View Article and Find Full Text PDFVolterra nonlinear equalizer (VNE) is widely used in intensity modulation and direct detection (IM/DD) systems because it employs multi-order operations to effectively capture the nonlinear characteristics of signals as a generic tool. In the specific directly-modulated laser with direct detection (DML-DD) link, the interaction between the chirp of DML and chromatic dispersion (CD) can be modeled as composite second-order (CSO) distortion. By incorporating the CSO model into the nonlinear equalizer, it is possible to better extract the feature of the end-to-end channel, achieving superior performance with lower complexity.
View Article and Find Full Text PDFWe report on the design of an all-mirror wavefront-division interferometer capable of spectroscopic studies across multiple spectral ranges-from the plasma frequencies of metals to terahertz wavelengths and beyond. The proposed method leverages the properties of laser sources with high spatial coherence. A theoretical framework for the interferometer scheme is presented, along with an analytical solution for determining the far-field interference pattern, which is validated through both optical propagation simulations and experimental results.
View Article and Find Full Text PDFEmploying free-running laser/envelope detection-based millimeter wave (mmWave) signal generation/detection at remote radio heads (RRHs)/user equipment (UE) offers a cost-effective solution for seamlessly integrating existing intensity modulation-direct detection (IM-DD)-dominated optical access networks and wireless networks. Such fiber-wireless convergence enables a continuous flow of signals with varying characteristics between the baseband unit (BBU) and UE across fiber and wireless network segments without the need for optical-electrical-optical (O-E-O) conversions and digital signal processing (DSP) at intermediate nodes. In this paper, we extensively investigate the performance of such a fiber-wireless converged access network employing free-running laser/envelope detection-based mmWave generation/detection in an IM-DD-based 1.
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