Investigation of humidity effect on the air refractive index using an optical fiber design

Mehrabani, A ; Sharif University of Technology | 2011

906 Viewed
  1. Type of Document: Article
  2. DOI: 10.3923/jas.2011.3022.3027
  3. Publisher: 2011
  4. Abstract:
  5. In this study operation of an optical design based on the intensity modulation for the refractive index change has been described. The reported instrument measures the transmitted output power depending up on the medium refractive index in the light path of a fiber-to-fiber design. A liquid cell is located between the fibers in the light path and power variations for different cold and hot water levels in the cell are measured. By using a reference humidity meter the calibration curve representing the relative humidity (%RH) as a function of the transmitted output power is obtained. For the hot water with the final temperature of T = 32.7°C the output power range of 255.0 -313.OnW is measured for a relative humidity change of 32.76 -41.26%. A power variation of 58 nW is noted for the 8.5% RH variation which shows the high sensitivity for the reported sensor. For the light transmitted in dry air path the output power is 516.7 nW while for the water path such power is 784.6 nW. Thus, the reported device can check the presence of the water vapor, water, or any other transparent liquid in the gap between the two axially aligned fibers. Performance of the new system is satisfactory as a refractive index monitoring mean and for the water/water vapor sensing
  6. Keywords:
  7. Light detection ; Air refractive index ; Aligned fibers ; Calibration curves ; Dry air ; High sensitivity ; Hot water ; Humidity effects ; Intensity modulations ; Light path ; Liquid cells ; Optical fiber designs ; Output power ; Power variations ; Refractive index changes ; Transparent liquids ; Vapor sensing ; Atmospheric humidity ; Liquids ; Modulation ; Optical design ; Optical fibers ; Refractive index ; Sensitivity analysis ; Sensors ; Vapors ; Water levels ; Water vapor ; Fibers
  8. Source: Journal of Applied Sciences ; Volume 11, Issue 16 , 2011 , Pages 3022-3027 ; 18125654 (ISSN)
  9. URL: http://www.scialert.net/abstract/?doi=jas.2011.3022.3027