| Zugriffsnummer | 44320 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | Comparison measurements for selection of suitable photodetectors for use in Nd:YAG LDA systems |
| Autor(in); Institution |
Arndt, Volker; PTB-Braunschweig
Müller, Harald; 1.31, Strömungsmesstechnik, PTB-Braunschweig
Dopheide, Dietrich; 1.3, Fluidmechanik, PTB-Braunschweig
|
| Quelle/Jahr | Experiments in Fluids: 20 (1996), 460 - 465 |
| ISSN | 0723-4864 (PRINT) ; 1432-1114 (ONLINE) |
| DOI | |
| Verlag | Berlin [u.a]: Springer |
| Freie Schlagworte | Diode Laser ; Mode Laser ; Similar Comparison ; Comparison Measurement ; Special Technology |
| Zusammenfassung | Laser-diode-pumped Nd:YAG lasers (λ=1064nm) are compact, single-transverse mode laser sources with a higher output power than diode lasers (λ ˜ 800 nm). They are suitable light sources for miniaturized laser Doppler anemometer systems. On the other hand, the sensitivity of conventional detectors and the scattering efficiency particularly of particles smaller than 1 μm are reduced, when these light sources are used. The paper describes comparison measurements of commercial photodetectors based on Si, Ge and InGaAs in a test LDA with an Nd:YAG laser. The achievable signal-to-noise ratios (SNR) of the Doppler bursts versus the laser power in the measuring volume are compared. This shows that Silicon Avalanche photo diodes (APD) for the near-infrared using a special technology and InGaAs-APDs with low-noise pre-amplifiers can be used advantageously. Similar comparison measurements with an LDA system at λ=830 nm show that an Nd:YAG laser based LDA is more sensitive and leads to higher SNRs because of its higher output power, even though the Mie scattering efficiency and the detector sensitivity are reduced. |
