Light scanner having closed-loop control based on optical feedback

A system comprising:

• a source module comprising:
• a light scanner having a scanning element that is configured to receive a first light signal and steer (1) an interrogation signal in a first two-dimensional pattern over a scan region and (2) an optical-feedback signal in a second two-dimensional pattern over a first region, the interrogation signal including a first portion of the first light signal and the optical-feedback signal including a second portion of the first light signal, wherein the light scanner comprises a micromechanical system (MEMS) device that is a two-axis device having a first axis characterized by a first resonant frequency and a second axis characterized by a second resonant frequency;
• and
• a first package that contains the light scanner, the first package including a lid that is substantially transparent for the first light signal;
• a position monitor located in the first region, the position monitor configured to provide a feedback signal based on the optical-feedback signal;
• and
• a processor configured to estimate an instantaneous position of the scanning element based on the feedback signal.