Mode filter for LED-based absorption spectroscopy
| Autor: | Marian Rabe, Eric Ebert, Hendrik Kruger, Nils Damaschke, Hartmut Ewald |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Optical fiber Absorption spectroscopy business.industry 01 natural sciences law.invention 010309 optics Vibration Subwavelength-diameter optical fibre Wavelength Optics law Electromagnetic coil Filter (video) 0103 physical sciences Optoelectronics Medicine business Light-emitting diode |
| Zdroj: | I2MTC |
| DOI: | 10.1109/i2mtc.2016.7520591 |
| Popis: | A mode filter for LED-based gas absorption spectroscopy is shown. Two LEDs with different wavelengths are used for the measurement of gas concentrations. One wavelength for measurement and a second wavelength as reference. This allows to measure gases like NO2 (405nm) and SO2 (285nm). Different disturbances, like temperature, vibrations and the optical properties of LEDs require a mode filter to reduce their influences. The mode filter is eight-shaped. It is examined, how many windings on the mode filter are required to suppress the influence of disturbances. Three kinds of disturbances were evaluated: bending a fibre, shifting a fibre connector and changing the temperature of a fibre connector. An improvement with the mode filter is determined for different number of windings. For more than 7…8 windings on the mode filter, there is no significant improvement. Only the losses of the fibre system increase with an increasing number of windings. Mode filters are indispensable for a high sensitive sensor system. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|