Collective lasing from a linear array of dielectric microspheres with gain

Area of Science:

• Photonics
• Condensed Matter Physics
• Optical Engineering

Background:

• Dielectric microspheres are fundamental components in photonic devices.
• Coupling mechanisms in disordered photonic systems are crucial for light manipulation.
• Gain incorporation in such systems enables novel optical functionalities like lasing.

Purpose of the Study:

• To experimentally investigate the optical emission properties of a linear array of gainous dielectric microspheres.
• To understand the nature of emission modes, particularly collective lasing phenomena.
• To explore the influence of random arrangement on lasing characteristics and wavelength selectivity.

Main Methods:

• Experimental setup involving a linear array of randomly arranged, well-separated dielectric microspheres with gain.
• Characterization of optical emission spectra, focusing on longitudinal emission.
• Analysis of lasing thresholds and wavelength selectivity of the observed modes.

Main Results:

• Observation of resolution-limited, ultra-narrowband longitudinal emission modes.
• Evidence of collective lasing from the entire array, indicated by a distinct lasing threshold.
• Demonstration of strong wavelength selectivity in lasing, with preferred frequency bands and inhibition at others.
• Confirmation that this selectivity is independent of the degree of configurational randomness.

Conclusions:

• The collective emission from the gainous microsphere array exhibits lasing behavior.
• Individual microsphere Fabry-Perot resonances play a significant role in the observed wavelength selectivity of collective lasing.
• The findings offer insights into designing advanced photonic devices with controlled emission properties.