1. He-Ne laser
2. Side stage
3. Beam expander
4. Fixed mirror
5. Beam splitter
6. Compensator
7. F-P fixed mirror
8. F-P movable mirror
9. Coarse micrometer
10. Movable mirror
11. Fine micrometer
12. Movable stage
13. Glass screen
E/E': Eye observation
Fringe image acquired by color camera
Features
Two Interferometer Modes
Rigid and Precise
He-Ne Laser, Sodium-Tungsten Lamp, and Air Chamber Included
Optional VGA Video Camera for Fringe Image Display and Projection
Introduction
The LEOI-21 Michelson & Fabry-Perot Interferometer combines two fundamental interferometric setups—Michelson interferometer and Fabry-Perot interferometer—in one compact and rigid structure. The Michelson interferometer is essential for observing two-beam interference, whereas the Fabry-Perot interferometer enables the observation of multiple-beam interference and the measurement of the fine structure of spectra.
This equipment offers precise measurements in both interferometer modes and can easily switch between them. The setup is user-friendly, with straightforward component alignment, making it ideal for university and college physics teaching. An optional color camera can be used to display interference fringes on a VGA monitor or project them for real-time demonstrations in lectures.
The instruction manual contains comprehensive materials including experimental configurations, principles and step-by-step instructions. Please click Experiment Theory and Contents to find more information about this apparatus.
Using this instrument, the following experiment examples can be conducted:
1. Two-beam Interference observation
2. Equal-inclination fringe observation
3. Equal-thickness fringe observation
4. White-light fringe observation
5. Wavelength measurement of the Sodium D-lines
6. Wavelength separation measurement of the Sodium D-lines
7. Measurement of the refractive index of air
8. Multi-beam interference observation
9. Measurement of the He-Ne laser wavelength
10. Interference fringe observation of the Sodium D-lines
11. Interference fringe acquisition by color camera for VGA display or projector (optional)
Specifications
| Description | Specifications |
| Flatness of Beam Splitter and Compensator | 0.1 λ |
| Coarse Travel of Mirror | 10 mm |
| Fine Travel of Mirror | 0.25 mm |
| Fine Travel Resolution | 0.5 μm |
| Fabry-Perot Mirrors | 30 mm (dia), R=95% |
| Wavelength Measurement Accuracy | Relative error: 2% for 100 fringes |
| Dimension | 500×350×245 mm |
| Sodium-Tungsten Lamp | Sodium lamp: 20 W; Tungsten lamp: 30 W adjustable |
| He-Ne Laser | Power: >2.0 mW; Wavelength: 632.8 nm |
| Air Chamber, Pump with Gauge | Chamber length: 80 mm; Pressure range: 0-40 kPa |
Camera with VGA Port (Optional) | Sensor size: 1/4" |
| Resolution: 1280 × 1024 | |
| Pixel size: 2.8 μm × 2.8 μm | |
| Bit: 8 | |
| Output format: VGA | |
| Length measurement on screen with crosshairs | |
| Function setting & operation: via keypad and menu |
Part List
| Description | Qty |
| Interferometer Main Frame | 1 |
| Ground Glass Screen | 1 |
| Alignment Aperture | 1 |
| Sodium-Tungsten Lamp with Power Supply | 1 set |
| He-Ne Laser with Power Supply | 1 set |
| Air Chamber with Gauge | 1 set |
| Manual Counter | 1 |
| CMOS VGA Camera with Mount & Keypad (Optional) | 1 set |
1. He-Ne laser
2. Side stage
3. Beam expander
4. Fixed mirror
5. Beam splitter
6. Compensator
7. F-P fixed mirror
8. F-P movable mirror
9. Coarse micrometer
10. Movable mirror
11. Fine micrometer
12. Movable stage
13. Glass screen
E/E': Eye observation
Fringe image acquired by color camera
