2018-04-09 00:24

3 files changed, 35 insertions, 0 deletions

diff --git a/opa_phase/430 seconds.png b/opa_phase/430 seconds.png
new file mode 100644
index 0000000..e9c5cf5
--- /dev/null
+++ b/opa_phase/430 seconds.png
diff --git a/opa_phase/chapter.tex b/opa_phase/chapter.tex
new file mode 100644
index 0000000..774ab45
--- /dev/null
+++ b/opa_phase/chapter.tex
@@ -0,0 +1,35 @@
+\chapter{Abandon the random phase approximation} \label{cha:rpa}
+
+Recently we've made some measurements that seem to imply phase stability between the fs OPAs.  %
+We've typically assumed that the OPAs have random phase on every shot, making coherent heterodyne
+processes average to zero.  %
+These measurements show that this is a very bad assumption.  %
+
+I've taken the interferogram of OPA1 vs OPA2, Clearly the OPAs remain phase locked for many shots.  %
+In 'over time' I show the spectral phase pattern (D = 500 fs) for 1000 single shot acquisitions
+over 430 seconds in lab time.  %
+The phase does drift, but it is certainly not quickly randomized.  %
+
+I have more data showing:
+How the spectral phase changes over the course of hours.
+How the phase evolves as we scan the OPAs against each-other in color.
+The reproducibility of phase as the OPA motors move away and then return to a given color.
+
+I'll work this data up and send out another email with many more details and thoughts once I have
+time.  %
+This quick note is just to let the group know that we must abandon the 'random phase' assumption
+when thinking about what heterodyne processes can happen as coherent artifacts.  %
+
+\begin{figure}
+  \includegraphics[width=\textwidth]{"opa_phase/cross interference"}
+  \caption[CAPTION TODO]{
+    CAPTION TODO
+  }
+\end{figure}
+
+\begin{figure}
+  \includegraphics[width=\textwidth]{"opa_phase/430 seconds"}
+  \caption[CAPTION TODO]{
+    CAPTION TODO
+  }
+\end{figure}
diff --git a/opa_phase/cross interference.png b/opa_phase/cross interference.png
new file mode 100644
index 0000000..8891214
--- /dev/null
+++ b/opa_phase/cross interference.png