Extinction ratio

The extinction ratio of a laser in an optical transmission link is defined as the ratio of the optical power for a logic 1 signal to the power for a logic 0 signal. Ideally, the extinction ratio should be infinite. However, the ratio must be finite in an actual system in order to reduce the rise time of the laser pulses [16]. The nonzero power transmission for a bit of logic 0 causes the power penalty. The power penalty due to the extinction ratio (in linear units) is estimated by 

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For a microring resonator with a waveguide width of 5 pm and coupling gap of 200 nm, a resonance extinction ratio of 12 dB for TE polarization and 9 dB for TM polarization has been achieved, as shown in Fig. 2.10. The ring resonator had a race track shape with circular sections of 500 pm radius and straight coupling section of 100 pm in length. The width of the two exposed strips is about 50 pm. 

The ability to measure small index perturbations, (I/Ven. depends on the depth (i.e., the extinction ratio at resonance) and width of these resonances. The depth and width in turn depend on the relative values of the coupling coefficient t and the resonator loss a. Figure 9.16 shows typical ring resonator spectra calculated for two different loss values. The maximum extinction ratio is obtained at critical coupling when t = a, and the output intensity at resonance is exactly zero. The width of the resonances depends on the total round trip resonator loss, at, which is the product of waveguide losses within the ring (a) and coupling loss (t) at the coupler. 

The LUT algorithm retrieves values and uncertainties of Re[[ by comparing ratios of extinctions from SAGE II and CLAES (e.g., Ej/Eo J to pre-computed extinction ratios which are based on a range of unimodal lognormal size distributions, The precomputed ratios are presented as a function of for a given size distribution width crs. This establishes the range of RtI consistent with the measured spectra and error bars for... 

By studying the UV spectra of 1,2- and 2,3-condensed pyrimidin-4-ones. Allen et al,348 established that the main absorption bands of the 2-oxo-2H-and 4-oxo-4//-pyrido[ 1,2-a]pyrimidines fall into three regions (a, fi, and c) and that the intensities of the absorption maxima and the molar extinction ratios (i c/cb) are characteristic for the isomeric compounds (see Table II). 

Recently, true circular polarizers have been developed and are available from commercial sources. These are fashioned by sandwiching a chiral nematic liquid crystal between parallel glass windows. These devices are characterized by a high transmission and extinction ratios greater than 1000. They operate over a fairly narrow range of wavelengths about a central wavelength. 

The resulting device with total device length of 8 mm exhibited a good performance with an extinction ratio of approximately 9 dB, operating voltage of 5 V, optical loss of 0.2 dB cm and insertion loss with 3.5 dB cm [135]. Considering that temporal and thermal stabilities of this hybrid system are excellent, the E-O device fabricated by hybrid material has great potential for opto-electronic applications. 

Global climatologies of stratospheric aerosols have been produced from observations by satellite instruments. Hitchman et al. (1994), for example, have provided meridional distributions of measured extinction ratios based on 9 years of data from the Stratospheric Aerosol and Gas Experiment (SAGE I and II) and the Stratospheric Aerosol... 

Cytochrome c. Reduced lorm crystallizes as separate needles oxidized form as rosettes. Mol wt about 13,000. Extinction ratio = I. [5-1 23 Eg,550nm ... 

Cytochrome cy Identity with cytochrome e Keilin, Har-tree, Nature 176, 200 (1955). Extinction ratio ... 

The optical system used to assess flow-induced birefringence consisted of a 2-mW polarized He-Ne laser focused by a condenser lens on the center of the flow field. The birefringence patterns are observed between crossed polars by using a quarter wave (X/4) retardation plate as a Senarmont compensator. The polarized laser has an extinction ratio of 100 1 the polarizer and analyzer are Carl Zeiss components with extinction ratios of approximately 10... 

In this model, the symbols have the following meaning. ( )R(a3) ao(l)HD(a3) is the optical rotation produced by the vapour and depends on the number of absorption lengths ao and on the lineshape function D(o)) which takes the form of a Doppler-broadened dispersion curve for magnetic and electric field induced rotation ( )r will depend on the strength of the field and D(oa) on the direction and type of field (see table 2). The transmitted intensity 1 - Ij exp[-aoG(o))] where the lineshape function G(o)) for a single spectral component can usually be accurately described by a Doppler-broadened Lorentzian curve. Finally the terms B and C in equation (53) represent respectively the finite extinction ratio of the polarisers and a laser independent... 

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