a bstra ct   background: continuous high - intensity noise in the neonatal intensive care unit (nicu) is stressful for premature infants and its reduction is considered as a nursing care. this study aimed to evaluate the effects of earmuffs’ use on the physiologic and motor responses of premature infants.   materials and methods: this is a clinical trial conducted on 64 premature infants admitt...

We report on the first demonstration of velocity-matched distributed photodetectors and balanced photodetectors with p-i-n photodetectors. Record-high linear dc photocurrent of 45 mA has been achieved without suffering from thermal damage, thanks to the superior power handling capability of p-i-n photodiodes. A novel fiber alignment technique has been developed to achieve high linear photocurre...

We present our recent work on high-speed optical interconnects with advanced modulation formats and directly modulated 850 nm VCSELs. Data transmission at nearly 100 Gbps was achieved with 4-PAM. Forward error correction, equalization and preemphasis are also explored. The system aspects of the advanced modulation formats and their impact on the VCSEL requirements are discussed. Requirements on...

Optical code division multiple access (OCDMA) is one of the most upcoming technologies for future multiple access techniques along with WDMA and OTDMA. Optical CDMA offers greater scalability than other optical multiplexing technique and it provides flexible quality of service and data access security. OCDMA requires increasing demand for high speed, large capacity communications in optical net...

Kerr effect nonlinearities in optical fibres have been the subject of extensive studies [1 – 3]. Four wave-mixing (FWM) between the signal and the amplified spontaneous emission (ASE) noise was found to be an important source for system performance degradation, especially in systems using in-line optical amplifiers. With positive fibre dispersion, this effect is known as modulation instability ...

Passive optical network topology has been widely adopted in access networks due to its low-cost and yet flexible network structure. To further promote the passive optical networks, the cost reduction of optical modules is critical. Relatively expensive combination of a conventional index-coupled distributed feedback laser diode (IC-DFB-LD) and an optical isolator is commonly used for passive op...

In this paper, a stochastic term is added to the classical generalized nonlinear Schrödinger Equation to describe the noise generated when light pulses propagate in a fiber. It has been shown that the generated supercontinuum light source fluctuates up to 50% of its output temporal intensity profile due to noises of different sources. The simulation method devised has been applied to the propag...

Intensity difference limens (DLs) were measured in users of the Nucleus 22 and Clarion v1.2 cochlear implants and in normal-hearing listeners to better understand mechanisms of intensity discrimination in electric and acoustic hearing and to evaluate the possible role of neural adaptation. Intensity DLs were measured for three modes of presentation: gated (intensity increments gated synchronous...