1. Basic principles

The working principle is based on interference effects. When two coherent light beams meet, if there is a phase difference between them, an interference pattern will be generated. During the thickness measurement process, the infrared beam undergoes reflection and transmission through the material being measured, resulting in interference phenomena. By analyzing the changes in the interference fringes, the thickness of the material can be accurately calculated.

2. Structural composition

The basic structure usually includes the following parts:

2.1 Light source

The light source is an important component, usually using infrared light emitted by lasers or LEDs. Infrared light has the characteristic of longer wavelength, suitable for penetrating some transparent materials, and has strong adaptability to the measurement environment.

2.2 Beam splitter

A beam splitter is used to split an incident light beam into two coherent beams. Usually, a beam splitter or fiber coupler is used to ensure that the phase relationship between the two beams of light remains consistent, thereby forming a clear interference pattern.

2.3 Reference arm and measuring arm

There are two main optical paths in a thickness gauge, one is the reference optical path, usually reflected by a beam splitter; The other is the measurement optical path, where the light beam reflects back to the measurement system after passing through the material under test. These two optical paths are designed with specific layouts to ensure the formation of interference patterns.

2.4 Detector

Detectors are used to receive interfered light signals, commonly including photodetectors or CCD cameras. The detector converts the received optical signal into an electrical signal and transmits it to the computer for data processing.

2.5 Data Processing System

The data processing system is responsible for analyzing the detected interference signals, calculating the thickness of the material through complex algorithms, and usually providing a user interface to display the measurement results.

3. Operation process

The operation process of using an infrared interferometric thickness gauge is relatively simple. The following are the general steps:

1. Preparation work: Ensure that the instruments and equipment are functioning properly, perform necessary calibration, and ensure a stable measurement environment.

2. Sample placement: Place the material to be tested on the measurement plane, ensuring its surface is flat.

3. Light source on: Start the infrared light source, and the beam is split into reference light and measurement light through the beam splitter.

4. Interference pattern formation: The measurement light passing through the material meets the reference light to form an interference pattern.

5. Signal acquisition: The detector receives the interference pattern and converts it into an electrical signal.

6. Data processing: Transmit electrical signals to a computer for processing, calculate the thickness of the material, and display the results.

4. Application

Infrared interferometric thickness gauges are widely used in multiple fields, including:

Optical thin film: Accurate control of film thickness is crucial in the manufacturing of optical components, and thickness gauges can provide high-precision measurements.

Semiconductor industry: Measuring the thickness of thin films is very important in the production process of semiconductor devices. Infrared interference and its non-contact measurement characteristics reduce damage to materials.

Materials science research: When studying new materials, understanding the relationship between the microstructure and thickness of the material, thickness gauges can provide accurate experimental data.

Coating monitoring: In the coatings and coating industry, thickness uniformity affects product performance and can be used for real-time monitoring.

Conclusion

Infrared interferometric thickness gauge, as an advanced measuring tool, has become an important instrument in modern industry and scientific research due to its high precision, speed, and non-contact properties. In the future, with the continuous advancement of technology, it will demonstrate its unique value and application potential in more fields.