M.Sc Thesis

M.Sc StudentFisher Jonathan
SubjectMulti-Degree-of-Freedom (DOF) Extremum Seeking (ES)
Stabilization of Large-Scale Photonic-Integrated
Circuits (PIC)
DepartmentDepartment of Electrical and Computer Engineering
Supervisor PROFESSOR EMERITUS Moshe Nazarathy


A novel control and calibration (C&C) systematic approach, aiming at feedback stabilization of large scale photonic-integrated circuits (PIC) to their optimal operating points (OOP) in D-dimensional space of tuning parameters is presented. The approach is based on refinement of extremum-seeking (ES) real-time optimization techniques. The novel methodology enables, in principle, stabilizing a large number - D of tuning PIC’s degrees of freedom (DOFs), with just one (or several) optical power monitoring (probes) point(s).

The proposed C&C digital approach introduces multidimensional ES stabilization concepts to photonics for the first time and proposes novel improvements to known ES techniques. In addition, a new frame-based discrete-multitone method, akin to an orthogonal-frequency-division multiplexing (OFDM) modulation format, of actuation signals generation and probe signals detection is presented, enabling simultaneous stabilization of multiple coupled tuning degrees of freedom by virtue of the decoupling of the orthogonal linear and nonlinear excitations due to the usage of the OFDM frequency grid.

The new technique is exemplified by numeric simulations of operating point stabilization of the following photonic integrated circuit structures:

1.      Microring based BPSK modulator with D = 2 tuning DOFs

2.      IQ modulator with D = 3 tuning DOFs

3.      MIMO equalizer  for 2 , 3 , 4 modes with D = 2 , 6 , 12  tuning DOFs (respectively)