Sept. 14 2001

Today is the first day I come to lab to do some experiment. First I
set up the equipment and then adjust the two mirrors to make the laser
beam parallel to the desk plane. To catch the laser into the fiber is
somewhat like find a golf ball in football field. Fortunately, I
succeed in catching the laser beam into fiber.  I also measure the
intensity of laser beam at the beginning and the end of the fiber with
photodetector.


Sep. 19 2001

I read some of materials about the fiber optics. I get some idea about
the fiber. And I also read the web report of Xueqing's and Xiyue's
experiment.


Sep. 21 2001

I observe the oscillation of the light of he light intensity at the
end the fiber through oscilloscope. And I get the similar result as
Xiyue's.


Sep. 25 2001

I read some fiber optics tutorial through web; most of them are from
the result of the search by "google". I specially read about the NA
(Numerical Aperture).


Sep. 28 2001

I measure the NA value of single mode fiber. To measure the diameter
of mode field, I first measure the Gauss profile by using the
photodetector. After the analysis by Origin I get a beautiful graph of
Gauss profile. And after calculation I get the value of NA, and it is
less than the value supposed to be.


Oct. 5 2001

With the help of Dr. John Noe, I measure the Gauss profile of green
laser beam. Also I get the NA of fiber by using different wave length
laser beam.