A study of the neutral atomic iodine laser

Area of Science:

• Atomic Physics
• Laser Science
• Plasma Physics

Background:

• Investigates laser action in neutral atomic iodine (I I) involving electronic transitions between 5d and 6p energy levels.
• Examines the impact of different excitation methods on laser performance.

Purpose of the Study:

• To analyze and enhance the power output of helium-iodine lasers.
• To understand the underlying physical mechanisms responsible for laser action and population inversion.

Main Methods:

• Experimental setup utilizing direct current (DC) and superimposed radio frequency (RF) excitation of a helium-iodine discharge plasma.
• Measurement of electron temperature and density under superimposed excitation conditions.
• Spectroscopic analysis of spontaneous intensities for laser lines and related transitions.
• Calculation of Einstein A coefficients to determine population densities, pumping rates, radiative lifetimes, and gains.

Main Results:

• Superimposed RF excitation significantly improves laser power output compared to DC excitation alone.
• Electron temperature and density were measured at 1.0 x 10^5 K and 5.0 x 10^11/cm^3, respectively, under superimposed conditions.
• Strong population inversions were observed for 5dJ = 7/2, 9/2 levels, where direct radiative relaxation to the ground state is forbidden.

Conclusions:

• The combination of DC and RF excitation is an effective method for boosting helium-iodine laser performance.
• Multistep deexcitation processes are proposed as the primary mechanism explaining the observed laser characteristics and population inversions.
• Understanding these processes is crucial for optimizing laser design and performance.