ELECTRONICS TEXT BOOKS

ELECTRONICS TEXT BOOKS:

1. LINEAR INTEGRATED CIRCUITS BY-SALIVAHANAN


2. Linear Integrated Circuits BY U.A bakshi
3. Linear Integrated Circuits by Visvesvara Rao B.
4. BASIC ELECTRONICS: DEVICES, CIRCUITS AND IT FUNDAMENTALS by santiramkal .
5. Basic Electronics and Linear Circuits by N. N. Bhargava
6. Basic Electronics by Rakesh Kumar Garg, ‎Ashish Dixit, ‎Pavan Yadav
7. Basic Electrical and Electronics Engineering: by S.K. Bhattacharya
8. Op Amps for Everyone byBruce Carter, ‎Ron Mancini
9. ELECTRONICS LAB MANUAL (VOLUME 2) by NAVAS, K. A.
10. LABORATORY EXPERIMENTS AND PSPICE SIMULATIONS IN ANALOG ELECTRONICS by L. K. MAHESHWARI, ‎M. M. S. ANAND 
11. Operational Amplifier Circuits by Brian C.J. Moore, ‎John Donaghy
12. Operational Amplifiers and Linear Integrated Circuits by k lalkishore
13. Electronic Circuits and Systems : Analog and Digital,by B N BAPAT
14. ANALOG AND DIGITAL COMMUNICATION BY SINGAL

       15 .  LINEAR INTEGRATED CIRCUITS BY D ROY CHWDARY

Double refraction

Double refraction:

1) In 1869 Erasmus Bartholinus discovered that when a beam of ordinary unpolarized light is passed through a calcite crystal,the refracted light is split up in to two refracted rays.

The one which obey the ordinary laws of refraction and having vibrations perpendicular to the principal section is known as ordinary ray. The other in general , does not obey the laws of refraction and having vibrations in the principal section is called as extra ordinary ray. Both these rays are plane polarized. This phenomenon is known as double refraction.

2) A beam of unpolarised light incident on the calcite crystal at an angle of incidence 'r' as shown in fig. Inside the crystal, the ray breaks up in to the ordinary and extraordinary rays. The ordinary ray travelling along RO makes an angle of refraction 'r1' while the extraordinary ray travelling along SE makes an angle of refraction 'r2'. The two opposite faces of the crystal are always parallel ,both the rays emerge parallel to the incident rays.

The refractive indices of ordinary and extraordinary rays can be expressed as

µ₀= sin r/sin r1  and µ_i = sin r/ sin r₂

3) The velocity of light for ordinary ray inside the crystal will be less then the extraordinary ray .the refractive index of ordinary ray is same for all the angles

of incidence while the refractive indices of extra ordinary ray varies with angles

of incidence.ordinary ray travels with the same speed in all directions while extra ordinary ray has different speeds in different directions.

Scattering loss

Scattering loss

Scattering losses in glass arises from macroscopic variations in the material density From compositional Fluctuations and from structural inhomogeneities or defects occurring during

 fibre manufacture.
    
Glass is made up of several oxides ,such as Sio2,Geo2, and P2O5 compositional fluctuations 

can occur.Glass structure naturally contain regions in which the molecular density is either

higher or lower than the average density in the glass. These two effects give rise to

refractive index variations which occur with in the glass over distances that are small compared with the wavelength.

For a single component glass the scattering loss at a wavelength λ resulting from density fluctuations

can be given as

where n is the refractive index ,K_B is Boltzmann constant , β_{T is the isothermal compressibility of the} 

_{material , and} T_{f  is fictive temperature.}

_{alternately we use other relation}

   

where p is the photo elastic coefficient .

for multicomponent glasses the scattering is given by

                                                  

where is square of mean square refracive index fluctuations  over volume of 

structural inhomogeneities and defects created during fibre fabrication  can also cause

 scattering of light out of the fibre. these defects may be in the form of trapped 

gas bubbles ,unreacted starting materials,and crystallized regions in the glass.

the losses of multimode fibres are generally higher than those of single mode fibres.

                                                     

    

Absorption loss

Absorption is caused by three different mechanisms:
1)Absorption by atomic defects in the glass composition
2)Extrinsic absorption by impurity atom in the Glass material
3)Intrinsic absorption by the basic constituent atoms of the fibre material  

Atomic defects are imperfections in the atomic structure of the fibre material.ex:missing molecules ,high density clusters of atom groups, or oxygen defects in the glass structure. absorption losses arising from these defects are negligible compared with intrinsic and impurity absorption effects.

Radiating damages a material by changing its internal structure. the damage effects depend on the energy of the ionising particles or rays ,(eg; electrons,neutrons or gamma rays), the radiation flux , and the flounce.the total dose a material receives is expressed in units of  rad(Si),which is a measure of radiation absorbed in bulk silicon. 

                                               1rad(Si)= 100erg/g =0.01j/kg
The basic response of a fibre to ionising radiation is an increase in attenuation owing to the creation of atomic defects , or attenuation centres , that absorb optical energy . for the higher radiation level , the  attenuation is larger .

The other dominant absorption factor in fibres are preparation of fibre materials. fibre materials prepared by the direct-melt method is in  the presence of impurities .impurity absorption results predominantly from transition metal ions ,such as iron,chromium,cobalt,and copper,and from OH(water) ions.the transition metal impurities which are present in the starting materials used for direct-melt fibres range between 1 and 10 parts per billion ,causing losses from 1 to 10 dB/km. the impurity levels in vapour-phase deposition processes are usually 
one to two orders of magnitude lower .Impurity absorption losses occurs either because of electronic transitions between energy levels or because of change transitions from one ion to another.

Intrinsic  absorption is associated with the basic fibre material (sio2) and is principle physical
factor that defines the transparency window of a material over a specified spectral region. it 
is observed in the ultra violet region and from atomic vibration bands in the near  - infrared 
region. 
The electronic absorption bands are associated with the band gap of the amorphous glass materials.this absorption occurs when a photon interacts with an electron in the valence band and excites it to a higher energy level.

The  ultra violet edge of the electron absorption bands of both amorphous and crystalline material follow the empirical relation ship

                                        α_uv=ce^E/E0

^{which is known as urbach's rule.}

the ultra violet loss in dB is  α_uv=  1542  x       X 10^-2  exp(4.63)   

                                                            46.6 x+60                       (  λ)