Wavelength Phase-Shifting Laser Interferometer for Multisurface Measurement
Because lasers have good coherence, measuring a plane-parallel optical element produces interference fringes between its front surface and the interferometer reference, between its rear surface and the reference, and between the front and rear surfaces themselves. These three fringe sets overlap, and conventional methods cannot directly analyze such an interferogram. A common approach is to coat the sample's rear surface with grease such as petroleum jelly. With a refractive index close to1.5, similar to most optical glasses, the grease acts like a roughened rear surface and removes unwanted rear-surface interference. However, it risks contaminating the sample and is ineffective for high-index optical glass. Multi-surface measurement technology (MST) provides a solution. It uses a wavelength-tunable laser: wavelength-induced phase shifts depend on cavity length, giving each fringe set from a plane-parallel optical element a unique cavity-length-related frequency. By analyzing a single acquired dataset, Shineoptics' multi-surface measurement algorithm independently separates the profiles of the parallel surfaces. A single measurement therefore directly yields three characteristics: front-surface figure, rear-surface figure, and optical-thickness variation.
Overview
Specifications
| Parameter | Value |
|---|---|
| Laser Center Wavelength | 633nm |
| Output Power | 2mw |
| Coherence length | >50m |
| Tuning Range | 500GHz |
| Separable Test Thickness | >1mm |
| Software Functions | Measurement of parallel-plane surface figure, parallel-plane optical homogeneity, and thickness difference |
| Measurable Parameters | Surface figure PV, RMS, POWER values, etc.; optical homogeneity; TTV |
Key Features
Datasheet
Supplier Information
Loading...
Name
Phone
Organization
Use Case

Database Platform