In this paper we present the development of an electro optical «Bragg» modulator for telecommunication, in both design and fabrication. The device consists from a regular single mode silicon waveguide (WG) in which an effective Bragg reflector is «turned on» within the WG by means of external bias, due to the plasma dispersion effect, in which the (complexed) refractive index is affected by carrier concentration within the Silicon. Three different strategies are presented for both design and fabrication.

In this paper we present a design as well as the fabrication procedure of a new type of electro-optical modulator based on plasma dispersion effect. The device consists from a regular single mode silicon waveguide and periodically patterned electrodes made out an indium thin oxide (ITO) located along both sides of the optical core through which the photonic signal is propagating. By applying voltage on the electrodes a periodic change in the free electrons is occurred along the optical core. This change affects both the imaginary and real part of the refractive index resulting in the generation of periodic change in the refractive index that creates an effective Bragg reflector. Different fabrication strategies are reported. (C) 2013 Elsevier B.V. All rights reserved.

In this work, we have fabricated a porous silicon (PSi) Bragg reflectors microarray using a proper technological process based on photolithography and electrochemical anodization of silicon. Each element of the array is characterized by a diameter of 200 mu m. The PSi structures have been used as platform to immobilize label-free DNA probe and a simple optical method has been employed to investigate the interaction between probe-DNA and its complementary target. In order to confirm the specificity of the DNA hybridization, we have also verified that the reaction of probe-DNA with non-complementary DNA did not occur.

From measurements performed on a low-noise two-stage SQUID amplifier coupled to a high-Q electrical resonator we give a complete noise characterization of the SQUID amplifier around the resonator frequency of 11 kHz in terms of additive, back action and cross-correlation noise spectral densities. The minimum noise temperature evaluated at 135 mK is 10 ¼K and corresponds to an energy resolution of 18 hbar

Starting from the measured parameters of multilayer microcavities activated by Er3+ ion, we developed a comprehensive model based on extended (3 x 3) transfer matrix formalism including sources. The cavity, fabricated by rf-sputtering technique, was constituted by an Er3+-activated SiO2 active layer inserted between two six-pair SiO2/TiO2 distributed Bragg reflectors. Near infrared transmittance spectra evidence the presence of a stop-band from 1350 to 1850 nm and a cavity resonance centered at 1537 nm. Intensity enhancement and narrowing of the 4I13/2 à 4I15/2 emission band of Er3+ ion were observed, owing to the cavity effect. A cavity quality factor of 171 was achieved. All observations show excellent agreement with transfer matrix simulations, leading to improvements of the devices design operating in laser regime.

In this letter, we present a novel structure for light amplitude modulation based on a lateral p-i-n diode combined with a Bragg reflector which transforms the phase shift induced by the plasma dispersion effect in the intrinsic region of the diode into a voltage controlled variation of the reflectivity of the Bragg mirror. Numerical simulations show a modulation depth of 50% achieved in about 12 ns with a power dissipation of 4.0 mW and an insertion loss of 1.0 dB. The device is demonstrated to be very attractive in terms of power dissipation as compared to a Mach-Zehnder interferometer occupying the same area on chip. © 1997 American Institute of Physics.