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Using Microwave and Macroscopic Samples of Dielectric Solids to Study the Photonic Properties of Disordered Photonic Bandgap Materials
Published on: September 26, 2014
Transition of lasing modes in disordered active photonic crystals
1Institute of Textiles and Clothing, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Optics Letters
|September 18, 2007
Summary
Disorder in two-dimensional active photonic crystals causes a shift in lasing modes from the band edge to the band gap, transitioning from photonic band-edge lasers to random lasers.
Area of Science:
- Photonics
- Condensed Matter Physics
- Laser Physics
Background:
- Two-dimensional active photonic crystals exhibit unique light-matter interactions.
- Photonic band-edge lasers operate at the edges of photonic band gaps.
- Random lasers offer alternative lasing mechanisms based on disorder.
Purpose of the Study:
- To investigate the transition from photonic band-edge lasers to random lasers in disordered 2D active photonic crystals.
- To analyze the effect of disorder on the lasing modes within the photonic band gap.
- To understand the influence of gain profiles on mode modulation.
Main Methods:
- Fabrication and characterization of 2D active photonic crystals with controlled disorder (positional and size variations).
- Optical spectroscopy to observe lasing modes and their spectral positions.
- Theoretical modeling to simulate mode shifts under different gain conditions.
Main Results:
- Introduction of disorder shifts lasing modes from the photonic band edge towards the bulk of the band gap.
- The degree of mode shift is dependent on the amount and type of disorder.
- Significant modulation of lasing modes occurs when the transition wavelength overlaps the photonic band gap, especially with specific gain profiles.
Conclusions:
- Disorder is a critical factor in controlling laser behavior in 2D active photonic crystals.
- The transition to random lasing is facilitated by disorder-induced mode redistribution within the band gap.
- Gain profile engineering can further tune the lasing characteristics in disordered photonic systems.
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