Leave a message for inquiry
Leave your phone number, and we'll get in touch with you as soon as possible.
Longitudinal Mode Measurement——Scanning F-P Interferometer
The longitudinal mode of a laser refers to the axial distribution of the light field along the direction of propagation. A typical laser oscillator usually supports several to dozens of longitudinal modes that can lase simultaneously. When tested with a high-resolution spectroscopic instrument, the output laser spectrum reveals multiple laser frequencies (or wavelengths). By employing selective-frequency techniques to suppress all but one of these modes, it’s possible to generate a single-longitudinal-mode (single-frequency) laser. Compared to conventional lasers, single-longitudinal-mode lasers boast narrower spectral linewidths and significantly longer coherence lengths, making them invaluable in applications such as spectroscopic analysis, holographic imaging, and interferometric measurements.
The scanning Fabry-Perot interferometer is a spectral analyzer designed to detect subtle spectral features of continuous lasers, comprising a sawtooth wave generator, a Fabry-Perot interferometric cavity, and a high-speed photodetector.
Testing Instrument: Scanning F-P Interferometer
- Confocal Fabry-Perot Design
- The reflectance of the lens remains above 99% in the range of 532-633 nm
- Photodiode Detector Included
- Free Spectral Range: 2.5 GHz
- Minimum Finesse: 200
| Model | Applicable Wavelength | Free spectral range | Precision | Resolution | Cavity length | Lens material |
| FPSI 200-532 | 532–633 nm (Other wavelengths are customizable) | 2.5GHz | ≥200 | <12.5 MHz | 30 mm | UV fused quartz |
Scanning F-P Controller Box
- Sawtooth Scan Voltage
- For Piezoelectric Transducer
- Scan the Separation between the Two Cavity Mirrors
- High voltage signal duty cycle and amplitude adjustment range are adjustable.
| Oscillogram | Output voltage range | Frequency Conversion |
| Sawtooth wave | 0-200V | 0.05/ 0.1/ 0.5/ 1/ 5s |
Examples of Testing Results
 |  |
Single longitudinal mode testing | Multiple longitudinal modes testing |
Changchun New Industries Optoelectronics Technology Co., Ltd.
Address: No. 888 Jinhu Road, High-Tech Zone, Changchun, 130103, P.R.China
International Tel:+86-431-85603799
Email: sales@cnilaser.com
Send a Message
Leave your phone number, and we'll get in touch with you as soon as possible.