Rami Arieli: "The
Laser Adventure" Chapter 4 Section 4, page 14
Applet: Stability Diagram of an
Optical Cavity
This applet let you change the parameters of the optical cavity of the
laser:

The radius of curvature of each of the cavity mirrors R_{1}
and R_{2}.

The cavity length L.
The computer will calculate the stability
factors: g_{1}, g_{2},
which appear on the right side of the stability diagram.
On the stability diagram there is a red point which shows the location
of the point (g_{1}, g_{2}).
When the red point is outside the dark region, the
cavity
is unstable.
On the right there is a message if the cavity is stable or not.
The structure of the cavity
is shown beneath the stability diagram.
Small blue points
on the cavity axis, mark the places for the center of the circles of the
radius of curvature for each mirror.
The yellow region marks
the active region of the cavity.
Activities:

Describe and explain what happened to the stability
of the cavity when you increase the radius of one of
the mirror from its maximum negative value (100 in the simulation) to
its maximum positive value (+100 in the simulation).
How is this effect shown on the stability graph?

For specific values of R_{1}, and R_{2}, What is the influence
of changing the length of the cavity on the cavity stability? (Check over
the entire range of cavity lengths available).