A two-dimensional laser scanning mirror using motion-decoupling electromagnetic actuators.

Area of Science:

• Optoelectronics
• MEMS (Micro-Electro-Mechanical Systems)
• Electromagnetics

Background:

• Traditional 2-D scanning mirrors often face limitations in achieving decoupled motion and compactness.
• Electromagnetic actuation is a key technology for precise mirror control in optical systems.

Purpose of the Study:

• To propose and validate a novel two-dimensional (2-D) laser scanning mirror with a compact and simplified actuating structure.
• To achieve decoupled scanning motions about orthogonal axes using a hybrid electromagnetic actuator design.

Main Methods:

• Finite element analysis (FEA) was employed to model and calculate magnetic flux within the electromagnetic system.
• Experimental validation was performed using a prototype 2-D scanning mirror (8 mm × 8 mm mirror size).
• Performance metrics including optical reflection angle, resonance frequency, and bandwidth were measured for both moving-coil and moving-magnet actuators.

Main Results:

• The upper moving-coil actuator achieved an optical reflection angle of 90° at 60 Hz resonance frequency (91 Hz bandwidth).
• The lower moving-magnet actuator demonstrated a 50° reflection angle at 60 Hz resonance frequency (88 Hz bandwidth).
• The prototype exhibited large 2-D angular deflections and a wide frequency bandwidth within a compact form factor (22 mm × 20 mm × 15 mm).

Conclusions:

• The proposed 2-D laser scanning mirror design successfully integrates moving-coil and moving-magnet principles for decoupled actuation.
• The device offers significant advantages in terms of angular deflection, operational bandwidth, and potential for low manufacturing cost.
• This compact scanning mirror is well-suited for applications requiring precise and efficient 2-D optical beam steering.