Equations you must know!

Classical:
    F = ma
    E = m(v*v)/2 = p*p/2m
    E_field = dV/dx
    Drift:    j = sigma*E_field
    Diffusion:  
         j_n =   qD_n dn/dx
         j_p = -qD_p dp/dx
   
Wave: (w is omega)

    Wave eq. in 1D.

    v_phase = w/k = lambda*f
    w = 2*pi*f
    k   = w/v_phase
    lambda = 2*pi/k

    Plane wave = A*exp(i(kx-wt))
        with absorbtion add exp(-alpha*x/2)
    Transverse --> E dot k = 0
   
 Quantum: ( h is "h bar")
    E = hw
    p = hk
  
    Free electrons -- E = h*h*k*k/2m
   
    Schrodinger Eq in 1D.

Devices
    Exitation over a barrier:  ~ exp(qV_b/kT)
    Diode:    I = Io*(exp(qV/kT)-1)
    Transistor: Ic = beta*Ib
    Optical Amp./Lasers:
             I = Io*exp(-alpha*x)
             alpha ~ n1-n2