Improves formatting and adds content on principle of operation.

references.bib

@@ -1,6 +1,6 @@
-@article{PhysRevLett.116.241103,
+@article{GW151226,
   title = {GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence},
-  author = {The LIGO Collaboration},
+  author = {The LIGO Scientific Collaboration},
   collaboration = {LIGO Scientific Collaboration and Virgo Collaboration},
   journal = {Phys. Rev. Lett.},
   volume = {116},
@@ -14,9 +14,9 @@
   url = {https://link.aps.org/doi/10.1103/PhysRevLett.116.241103}
 }
 
-@article{PhysRevLett.116.061102,
+@article{GW150914,
   title = {Observation of Gravitational Waves from a Binary Black Hole Merger},
-  author = {The LIGO Collaboration},
+  author = {The LIGO Scientific Collaboration},
   collaboration = {LIGO Scientific Collaboration and Virgo Collaboration},
   journal = {Phys. Rev. Lett.},
   volume = {116},
@@ -29,3 +29,24 @@
   doi = {10.1103/PhysRevLett.116.061102},
   url = {https://link.aps.org/doi/10.1103/PhysRevLett.116.061102}
 }
+
+@article{ALIGO,
+  title = {Advanced LIGO},
+  author = {The LIGO Scientific Collaboration},
+  journal={Classical and Quantum Gravity},
+  volume={32},
+  number={7},
+  pages={074001},
+  url={http://stacks.iop.org/0264-9381/32/i=7/a=074001},
+  year={2015},
+}
+
+@article{gires1964,
+  title = {Interferometre utilisable pour la compression d'impulsions lumineuses modulees en frequence},
+  author = {Gires F. and Tournois P.},
+  journal = {C. R. Acad. Sci. Paris},
+  volume = {258},
+  pages = {6112-6115},
+  year = {1964},
+  month = {Feb}
+}

scripts/gt_etalon.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+import matplotlib
+import matplotlib.pyplot as plt
+import numpy as np
+from math import atan, tan, cos, pi, sqrt
+
+matplotlib.rcParams.update({'font.size': 15})
+
+
+t0 = 4000.
+λ = 1064E-9
+t0 = λ*(3759398496+0.5)
+theta0 = 0.0
+n = 1.0
+
+
+def δ_(λ, n, t, theta):
+    return 4*pi*n*t*cos(theta)/λ
+
+
+def theta(r, h):
+    δ = δ_(λ, n, t0*(1+h), theta0)
+    return 2*atan(-tan(δ/2)*(1+sqrt(r))/(1-sqrt(r)))
+
+
+def main():
+    for r in (0, 0.5, 0.8, 0.986):
+        hs = np.linspace(-6.63E-11, 6.63E-11, 500)
+        ys = [theta(r, h) for h in hs]
+        plt.plot(hs, ys, label=f"R={r}")
+    plt.legend()
+    plt.ylabel("$\Phi$")
+    plt.xlabel("$h$")
+    plt.tight_layout()
+    plt.savefig("gt_etalon.png")
+    # plt.show()
+
+
+if __name__ == '__main__':
+    main()