Meandering waveguide distributed feedback structures are novel integrated photonic lightwave and microwave circuit elements. Meandering waveguide distributed feedback structures with a variety of spectral responses can be designed for a variety of lightwave and microwave circuit element functions. Distributed meandering waveguide (DMW) structures  show a variety of spectral behaviors with respect to the number of meandering loop mirrors (MLMs)  used in their composition as well as their internal coupling constants (Cs). DMW spectral behaviors include Fano resonances, coupled resonator induced transparency (CRIT), notch, add-drop, comb, and hitless filters. What makes the DMW special is the self-coupling property intrinsic to the DMW’s nature. The basic example of DMW’s nature is motivated through the analogy between the so-called symmetric meandering resonator (SMR), which consists of two coupled MLMs, and the resonator enhanced Mach-Zehnder interferometer (REMZI) . A SMR shows the same spectral characteristics of Fano resonances with its self-coupling property, similar to the single, distributed and binary self coupled optical waveguide (SCOW) resonators .
So far DMWs have been studied for their electric field intensity, phase  and phasor responses . The spectral analysis is performed using the coupled electric field analysis and the generalization of single meandering loop mirrors to multiple meandering distributed feedback structures is performed with the transfer matrix method. The building block of the meandering waveguide structures, the meandering loop mirror (MLM), is the integrated analogue of the fiber optic loop mirrors. The meandering resonator (MR) is composed of two uncoupled MLM’s. The meandering distributed feedback (MDFB) structure is the DFB of the MLM. The symmetric MR (SMR) is composed of two coupled MLM’s, and has the characteristics of a Fano resonator in the general case, and tunable power divider or tunable hitless filter in special cases. The antisymmetric MR (AMR) is composed of two coupled MLM’s. The AMR has the characteristics of an add-drop filter in the general case, and coupled resonator induced transparency (CRIT) filter in a special case. The symmetric MDFB (SMDFB) is composed of multiple coupled MLM’s. The antisymmetric MDFB (AMDFB) is composed of multiple coupled MLM’s. The SMDFB and AMDFB can be utilized as band-pass, Fano, or Lorentzian filters, or Rabi splitters.
Distributed meandering waveguide elements with extremely rich spectral and phase responses can be designed with creative combinations of distributed meandering waveguides structures for various novel photonic circuits.
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The devices that are variations of inter-and intracoupled meandering optical waveguides are proposed as the
lightwave circuit elements that exhibit distributed feedback. A preliminary transfer matrix method analysis is
applied in frequency domain, taking the coupling purely directional and with constant coefficient on geometrically
symmetric and anti-symmetric devices. The meandering loop mirror is the building block of all meandering
waveguide based lightwave circuit elements. The simplest uncoupled meandering distributed feedback structure
exhibits Rabi splitting in the transmittance spectrum. The symmetric and antisymmetric coupled meandering
distributed feedback geometries can be utilized as band-pass, Fano, or Lorentzian filters or Rabi splitters.
Meandering waveguide distributed feedback structures with a variety of spectral responses can be designed for
a variety of lightwave circuit element functions and can be implemented with generality due to the analytic