ABSTRACT
Figure 5.1 A schematic diagram of a nanoscale sensing transducer using PANDA ring resonator. Two identical beams of monochromatic optical field (Ein) of a Gaussian pulse with center wavelength 1.550 µm are launched in the system at the input and add ports. The monochromatic optical field is given by
in 0 0expE t E L j t a f (5.1) Here L = 2pRis the propagation distance (waveguide length), a the attenuation coefficient, and f0 the phase constant. When light propagates within the nonlinear material (medium), by considering the Kerr nonlinear effect within the ring devices, the refractive index (n) of light within the medium is given by20 2 0 effnn n n I n PA (5.2) Here n0and n2are the linear and nonlinear refractive indices, respectively. Iand Pare the optical intensity and optical power, respectively. The effective mode core area of the device is given by Aeff . The resonance output is formed, thus, the normalized output of the light field is the ratio between the output and input fields [Eout(t) and Ein(t)]in each roundtrip, which is given by the following equations [1, 4]:
(5.3) The optical output of ring resonator add/drop filter for the through and drop ports can be given by Eqs. 5.4 and 5.5, respectively [4].
