[Experiments of micro-distance measurement for GMLM with spectrum analysis method]

Area of Science:

• Optoelectronics
• Nanotechnology
• Optical Engineering

Context:

• Micro-Electro-Mechanical Systems (MEMS) are crucial for advanced display technologies.
• MEMS-based grating moving light modulators (GMLMs) require precise micro-distance measurements for optimal performance.
• Traditional measurement techniques are often destructive or prohibitively expensive.

Purpose:

• To develop a novel, non-contact, and cost-effective method for measuring the critical micro-distance in GMLMs.
• To analyze the GMLM optical principle using scalar diffraction theory.
• To validate the accuracy and repeatability of the proposed measurement technique.

Summary:

• A novel wavelength scanning spectrum analysis method was developed to measure the micro-distance between the movable grating and reflector in MEMS-based GMLMs.
• The method utilizes a U-4100 spectrophotometer and peak wavelength analysis, achieving a relative error below 1% compared to a WYKO White Light Interferometer.
• This technique offers a cost-effective (RMB 50 per measurement) and repeatable alternative for characterizing MEMS devices.

Impact:

• Enables precise characterization of MEMS devices without causing damage.
• Provides a low-cost alternative to expensive interferometric measurement tools.
• Facilitates further research and development in MEMS-based display technologies and other diffraction/interference devices.