| Description |
Effective pathlength for a prism compressor with A = 100 mm, θ = 55°, and α = 10°. The colors correspond to different values of B, where B = 67.6 mm means that the beam barely hits the tips of both prisms at refractive index 1.6. |
| Date |
9 July 2006(2006-07-09) |
| Source |
|
| Author |
Han-Kwang Nienhuys |
Hankwang, the copyright holder of this work, hereby publishes it under the following licenses:

 |
This file is licensed under the Creative Commons Attribution 2.5 Generic license. |
|
| Attribution: Hankwang |
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).
www.creativecommons.org/licenses/by/2.5 CC-BY-2.5 Creative Commons Attribution 2.5 truetrue
|
You may select the license of your choice.
|
[edit] Gnuplot script
Created with the following Gnuplot script (also by Han-Kwang and also GFDL/CC-By licensed)
# Calculate path lengths at different refractive indices in a prism compressor with a given geometry.
# Copyright Han-Kwang Nienhuys, 2006
# Licensed for distribution and modification according to the GFDL or CC-By licenses
# (which means basically: with proper attribution to the author)
pi=4*atan(1)
d2r=pi/180
sind(x)=sin(x*d2r)
cosd(x)=cos(x*d2r)
tand(x)=tan(x*d2r)
asind(x)=asin(x)/d2r
beta(n,alpha,theta)=asind(sind(alpha+theta)/n)
gam(n,alpha,theta)=theta-beta(n,alpha,theta)
delta(n,alpha,theta)=asind(n*sind(gam(n,alpha,theta)))
l1(n,alpha,theta,A)=A/cosd(delta(n,alpha,theta)) # pathlength through air
C(n,alpha,theta,A,B)=B-A*tand(delta(n,alpha,theta))
Bmin(n,alpha,theta,A,B1)=B1+A*tand(delta(n,alpha,theta))
# pathlength through 2nd prism. Undefined if the ray misses the prism.
l2(n,alpha,theta,A,B)=C(n,alpha,theta,A,B) < 0 ? 1/0 : C(n,alpha,theta,A,B)*sind(alpha+theta)/cosd(beta(n,alpha,theta))
D(n,alpha,theta,A,B)=l2(n,alpha,theta,A,B)*cosd(gam(n,alpha,theta))/sind(theta)
l3(n,alpha,theta,A,B)=D(n,alpha,theta,A,B)*sind(alpha+theta)
# A=distance between prism surfaces
# B=distance between prism tops (measured parallel to surface)
# theta=prism top angle
# alpha=indicent angle
# n=refractive index
pathlen(n,alpha,theta,A,B)=2*(l1(n,alpha,theta,A,B)+n*l2(n,alpha,theta,A,B) - l3(n,alpha,theta,A,B))
# difference with reference index n0. Specify B1 as distance from top where the n0
# ray hits prism 2.
n0=1.5
pathlenD(n,alpha,theta,A,B1)=pathlen(n,alpha,theta,A,Bmin(n0,alpha,theta,A,B1)) - \
pathlen(n0,alpha,theta,A,Bmin(n0,alpha,theta,A,B1))
set nogrid
set xlabel 'Refractive index'
set ylabel 'Path length difference (mm)'
set key bottom right
set samples 200
set xra [1.5:1.7]
set xtics 0.05
set ytics 1
A=100
n0=1.6
alpha=10
theta=55
set term svg fsize 24
set outp 'prism_compressor_curve.svg'
plot pathlenD(x,alpha,theta,A,0) ti 'B = 67.6 mm', \
pathlenD(x,alpha,theta,A,9) ti 'B = 76.6 mm', \
pathlenD(x,alpha,theta,A,18) ti 'B = 85.6 mm'
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment |
| current | 20:58, 10 February 2009 |  | 600 × 480 (12 KB) | Sarregouset | {{Information |Description=Effective pathlength for a prism compressor with A = 100 mm, θ = 55°, and α = 10°. The colors correspond to different values of B, where B = 67.6 mm means that the beam barely hits the tips of both prisms at refractive index |
The following pages on the English Wikipedia link to this file (pages on other projects are not listed):