titus
03-24-2002, 07:47 PM
Hello,
There has to be a better match between the air/water interface for more light to pass through. The following indicates the majority of light energy can not be passed into the seawater of our aquarium:
1) According to Material Properties (http://www.kgs.ukans.edu/Current/2001/martinez/martinez2.html), the relative permittivity of sea air and water are 1 and 80 respectively.
2) For light that has a horizontal polarization, reflection coefficient for materials that has a relative permittivity = 80 is very high, as shown in the following figure.
http://www.canreef.com/library/sea_water_horizontal_polarization_reflection.jpg
Note that, however, the frequency of red to blue light is 428THz - 750THz, which are much higher than the frequency used to measure the sea water permittivity in 1) above. Also, the Brewster angle for vertically polarized light is nearly 0. So if the light that we use has a vertical polarization then we're set.
Now the question is, what is the polarization for florescent and metal halide? Are they random, circular, elliptical, vertical, or horizontal? I guess this is going to be the next research project for Darren (DJ88) :eek:
[ 24 March 2002, 15:51: Message edited by: Titus ]
There has to be a better match between the air/water interface for more light to pass through. The following indicates the majority of light energy can not be passed into the seawater of our aquarium:
1) According to Material Properties (http://www.kgs.ukans.edu/Current/2001/martinez/martinez2.html), the relative permittivity of sea air and water are 1 and 80 respectively.
2) For light that has a horizontal polarization, reflection coefficient for materials that has a relative permittivity = 80 is very high, as shown in the following figure.
http://www.canreef.com/library/sea_water_horizontal_polarization_reflection.jpg
Note that, however, the frequency of red to blue light is 428THz - 750THz, which are much higher than the frequency used to measure the sea water permittivity in 1) above. Also, the Brewster angle for vertically polarized light is nearly 0. So if the light that we use has a vertical polarization then we're set.
Now the question is, what is the polarization for florescent and metal halide? Are they random, circular, elliptical, vertical, or horizontal? I guess this is going to be the next research project for Darren (DJ88) :eek:
[ 24 March 2002, 15:51: Message edited by: Titus ]