Extension of the dynamic range of liquid crystal tunable Lyot filter is demonstrated by incorporating with it a liquid crystal variable retarder as an eliminator for the third and fourth order peaks. The filter is continuously tunable in the range 500 nm to 900 nm with a nominal width in the range 50nm-100nm. Design procedure is described including the exact solution to the LC director profile ...

It is necessary to improve the analog preprocessing dynamic range. Special problem consists in minimisation of the noise and offset. The use of a tunable low-pass filter brings usually problems with increasing of the offset and drift. The survey of standard solutions of these problems is shown and new solution of this problem too. This new way consists in using crossover, which divide frequency...

Spatially coherent multicolored optical vector vortex beams were created using a tunable liquid crystal q-plate and a supercontinuum light source. The feasibility of the q-plate as a tunable spectral filter (switch) was demonstrated, and the polarization topology of the resulting vector vortex beam was mapped. Potential applications include multiplexing for broadband high-speed optical communic...

The increasing demand for multifunctional devices, the use of cognitive wireless technology to solve the frequency resource shortage problem, as well as the capabilities and operational flexibility necessary to meet ever-changing environment result in an urgent need of multiband wireless communications. Spectral filter is an essential part of any communication systems, and in the case of multib...

This paper focuses on the performance limits of a tunable-cavity Fabry-Perot filter (FPF) implemented using MEMS technology. This is a versatile device capable of many functions, including light modulation and high precision sensing. Our goal is to explore challenges and opportunities in implementing tunable-cavity filter using MEMS technology. Thermal stability and effects of fabrication imper...

A thermo-optically tunable multimode interference fiber laser is demonstrated. The laser emission can be easily tuned trough the C-band by simply changing the temperature around the multimode fiber liquid cladding of the filter. ©2011 Optical Society of America OCIS codes: (060.2410) Fibers, Erbium; (060.2310) Fiber Optics; (140.3600) Lasers Tunable; (060.4510) Optical communications

Tunable reflecting terahertz bandstop filter based on chirped metamaterial structure is demonstrated by numerical simulation. In the metamaterial, the metal bars are concatenated to silicon bars with different lengths. By varying the conductivity of the silicon bars, the reflectivity, central frequency and bandwidth of the metamaterial could be tuned. Light illumination could be introduced to c...

A tunable comb filter based on a fiber loop mirror setup, which incorporates a piece of pumped erbium-ytterbium co-doped polarization maintaining fiber, is newly presented. It is accomplished by controlling the pump power or adjusting a polarization controller in the loop mirror, which results from the fact that the effective birefringence of the erbium-ytterbium co-doped polarization maintaini...

A wideband tunable fiber ring lasers using 253.3-cm long La-codoped bismuth-based erbium doped fiber and a narrowband tunable MEMS filter are reported. The fiber ring laser is capable of tuning over 80 nm continuously from 1545 to 1625 nm with an average output power of -3 dBm and extinction ratio of 60 dB.

Th is paper presents a programmable resistor using two-input floating gate MOS transistor (FGMOST). One of the two-input gates is connected to the drain and the other is connected to a tuned voltage to control the floatin g gate transistor resistance. A wide range of the programmable resistance is achieved by controlling the tuned voltage. The resistance is changed by 33% by varying the tuned v...