the working condition of green laser pointer will be the best

 Therefore, the working condition of green laser pointer will be the best.
Confocal spherical interferometer reflectivity R and fine constant F between this experiment into the acousto-optic loss modulator to achieve mode-locking laser with 633nm He-Ne laser cavity. The gain characteristics of the He-Ne laser medium is a non-uniform broadening type. If the laser cavity length is not too short, there will be more than one laser longitudinal mode oscillation (in this experiment only discuss the fundamental transverse mode). Adjacent longitudinal mode circular frequency difference where c is the speed of light, L is the cavity length. If the gain linewidth of the laser medium is ΔωG, the N-longitudinal mode laser cavity will exist: in the cavity N longitudinal mode light field can be expressed as. In ω0 for the gain line width at the center of longitudinal mode frequency. Usually in the beginning of the N-longitudinal-mode free oscillation of the laser there is no fixed relationship between the phase φn. And it is good for maintaining green laser pointer .
Each other is a random variable. Average much larger than the longitudinal mode oscillation period of time (3) light force, and assuming that the longitudinal mode amplitude equal ie, En = E0 can be laser total intensity is proportional to the intensity of the longitudinal mode. Scanning interferometer observation of the longitudinal mode spectrum, we can see each longitudinal mode intensity random fluctuation. If we in some way so that a fixed link between the laser total initial phase of the longitudinal mode or synchronous oscillation to meet all longitudinal mode laser cavity longitudinal mode coherent superposition. The sake of simplicity, so that (3) φn = 0, and En = E0 (22) and (24), available comparison shows that the longitudinal mode of the phase synchronization, the original continuous output of light intensity into a light intensity change with time and space. It is the limited warranty of green laser pointer .
Now on a fixed space or a fixed time to observe changes in light intensity characteristics. When the fixed spatial position (so that z = 0) observed (24), the changes over time (t), the relative intensity. (25) has the following characteristics: N have the same frequency interval of the synchronous oscillation, allows laser light into a time-varying pulse sequence, pulse period T to T is a light pulse in the cavity round-trip propagation time required time.