We demonstrate for the first time the possibility of all-optical modulation of self-standing porous Silicon (pSi) membrane in the Mid-Wavelength Infrared (MWIR) range using femtosecond pump-probe techniques. To study optical modulation, we used pulses of an 800 nm, 60 femtosecond for pump and a MWIR tunable probe in the spectral range between 3.5 and 4.4 μm. We show that pSi possesses a natural...

Variable pulse position modulation (VPPM) is a new modulation scheme that supports simultaneously illumination with dimming control and communication. In this paper, the transmitter, optical wireless channel, and receiver structure of VPPM were modeled mathematically, and their error performance for examining the communication performance according to dimming level and data rate was analyzed. T...

In this paper, the implications of linear channel distortions in systems using envelope detection are reviewed and an equivalent baseband channel is formulated. Finally, the fibre optic channel is treated as a special case to analyse the impairments of Intensity Modulation/Direct Detection (IM/DD) systems employing Single Sideband (SSB) transmission.

Tokyo, 27 September 2005 --Hitachi, Ltd. (NYSE:HIT / TSE:6501) announced the successful development of a three-dimensional (3D) visualization technique to observe the amplitude and phase of high-speed optical signals in optical fiber communications, for the first time in the world. New methods of transmitting information using the phase of light (optical phase) through optical phase modulation ...

Visible Light Communication is the emerging field in the area of Indoor Optical Wireless Communication which uses white light LEDs for transmitting data and light simultaneously. LEDs can be modulated at very high speeds which increases its efficiency and enabling it for the dual purposes of data communication and illumination simultaneously. Radio Frequency have some limitations which is not a...

We present a novel high-speed transmitter consisting of a frequency modulated DBR laser and optical filters. The refractive index modulation in the phase control region of the DBR laser allows highspeed frequency modulation. The generated frequency modulated signal is converted to an intensity modulated signal using the edge of the optical filter pass band. We present theoretical simulations of...

In the wavelength division multiplexing passive optical network (WDM-PON) system, the modulation format was important. While three different modulation formats including not-return-to-zero (NRZ), return-to-zero (RZ), carrier-suppressed return-to-zero (CS-RZ) and the optical differential quadrature reference phase shift keying (DQPSK) modulation format of each code are introduced in the article....

Although gigahertz-scale free-carrier modulators have been demonstrated in silicon, intensity modulators operating at terahertz speeds have not been reported because of silicon's weak ultrafast nonlinearity. We have demonstrated intensity modulation of light with light in a silicon-polymer waveguide device, based on the all-optical Kerr effect-the ultrafast effect used in four-wave mixing. Dire...

Abstract: Modulator designs are proposed that can employ arbitrarily high-Q resonators to simultaneously achieve high energy efficiency and distortionless modulation at all (low/high) frequencies by completely decoupling optical cavity dynamics from the modulation frequency response. ©2010 Optical Society of America OCIS codes: (130.4110) Modulators; (130.3120) Integrated optics devices; (230.5...

We present a dynamical analysis of lossless intensity modulation in two different ring resonator geometries. In both geometries, we demonstrate modulation schemes that result in a symmetrical output with an infinite on/off ratio. The systems behave as lossless intensity modulators where the time-averaged output optical power is equal to the time-averaged input optical power.