5.6.1 Cavity power

This is a simple Finesse example showing the power enhancement in a two-mirror cavity as a function of the microscopic tuning of a mirror position (the position is given in degrees with \(360\degree\) referring to a change of longitudinal position by one wavelength). Compare this plot to the one shown in Fig. 27, which instead shows the power enhancement as a function of the laser frequency detuning (Fig. 34, generated here).

import finesse
from finesse.analysis.actions import Xaxis
finesse.init_plotting()

base = finesse.Model()
base.parse(
    """
    l l1 P=1                    # laser with P=1W at the default frequency
    s s1 l1.p1 m1.p1 L=1        # space of 1m length connecting laser to input mirror
    m m1 R=0.9 T=0.1            # cavity input mirror
    s scav m1.p2 m2.p1 L=1200   # cavity length of 1200m
    m m2 R=1 T=0                # cavity output mirror

    pd pd1 m2.p1.i              # photodiode measuring the intra-cavity power
    """
)

out = base.run(Xaxis(base.m2.phi, 'lin', -50, 250, 300))
out.plot(logy=True);