This project started a few years ago and the initial scope of the research was mainly focused on the investigation of sub-carrier multiplexed (SCM) WDM optical systems. As directed by Sprint, during the course of the research, we have expanded our focus to other digital modulation formats for high-speed optical transmission and the comparison of the system performance in various fiber types. In...

Multiple wavelength channels can be used for implementing transceiver modules in optical transmission system network in order to increase spectral efficiency. However, it leads to cost increment which is caused by employment of multiple optical components. Therefore, implementation of advanced modulation format has become an option to further increase spectral efficiency. But apparently, it inv...

Active control and cancellation of residual amplitude modulation (RAM) in phase modulation of an optical carrier is one of the key technologies for achieving the ultimate stability of a laser locked to an ultrastable optical cavity. Furthermore, such techniques are versatile tools in various frequency modulation-based spectroscopy applications. In this Letter we report a simple and robust appro...

performance of the fiber optic networks with different physical topologies such as point-to-point, bus, ring and star, with respect to requirements as bit rates, topology structure, bit. error rate (ber) and optical component characteristics including optical amplifiers, filters, sources and detectors, are analyzed and simulated. for this purpose, maximum number of supportable nodes and throug...

background: modulation of the immune response is an important strategy by which establish­ment and growth of hydatid cyst in the internal organs of human is warranted. induction of apop­tosis in the lymphocytes might be a considerable component. this study was designed to evaluate apoptotic impact of hydatid fluid (hf) on human lymphocytes. methods: human lymphocytes were treated with hydatid f...

Modulation techniques have attracted increasing attention in optical wireless communications. Basic schemes such as on off keying (OOK), pulse amplitude modulation (PAM) and pulse position modulation (PPM) have been validated as suitable for the optical wireless channel. This paper starts from the analysis of these three modulation schemes in terms of their power and bandwidth requirements. As ...

Spectrum efficient data transmission is of key interest for high capacity optical communication systems considering the limited available bandwidth. Transmission of the high speed signal with higher-order modulation formats within the Nyquist bandwidth using coherent detection brings attractive performance advantages. However, high speed Nyquist signal generation with high order modulation form...

Aims. Study the high-mass X-ray binary X-7 in M33 using broad-band optical data. Methods. We used recently published CFHT r ′ and i ′ data for variable stars in M33 to extract the light curve of the optical counterpart of X-7. We combined these data with DIRECT B and V measurements in order to search for an independent optical modulation with the X-ray periodicity. The periodic modulation is mo...

Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultralarge absorption bandwidth, and extremely fast material response. In particular, the opportunity to control optoelectronic properties through tuning of the Fermi level enables electro-optical modulation, optical-optical switching, and other optoelectronics applications. However, achieving a high mo...

this paper presents novel active filter for mitigation electromagnetic interference (emi) and other adverse effects of pulse width modulation (pwm) inverter-fed ac motor system. an active filter proposed and devised for this system is characterized by sophisticated connection of two small separate filters, capable of mitigating all the adverse effects. this paper provides high frequency models ...