Stimulated emission from donor transitions in silicon

Area of Science:

• Solid-state physics
• Optoelectronics
• Semiconductor science

Background:

• Far-infrared (FIR) lasers are crucial for spectroscopy and sensing.
• Stimulated emission in semiconductors offers potential for novel light sources.
• Shallow donor transitions in silicon have been explored for optical applications.

Purpose of the Study:

• To report the observation of far-infrared stimulated emission from shallow donor transitions in silicon.
• To demonstrate lasing at 59 µm in phosphorus-doped silicon (Si:P).
• To theoretically analyze the population dynamics and optical gain in the Si:P system.

Main Methods:

• Experimental observation of stimulated emission using a CO2 laser as a pump source.
• Fabrication and characterization of phosphorus-doped silicon samples.
• Theoretical modeling of donor center populations (D0 and D-) and radiation balance (absorption vs. amplification).

Main Results:

• Successful generation of stimulated emission at a wavelength of 59 µm.
• Achieved lasing due to the neutral donor intracenter 2p(0)-->1s(E) transition in Si:P.
• Theoretical analysis provided insights into population inversion and gain mechanisms.

Conclusions:

• Far-infrared stimulated emission and lasing are achievable in shallow donor transitions in silicon.
• Si:P serves as a viable material for FIR laser applications.
• The theoretical analysis supports the experimental findings and aids in understanding the lasing mechanism.