Unidirectional laser emission from π-conjugated polymer microcavities with broken symmetry
Author
Tulek, A.
Vardeny, Z.V.
Date
2007Source Title
Applied Physics Letters
Print ISSN
0003-6951
Volume
90
Issue
16
Language
English
Type
ArticleItem Usage Stats
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Abstract
We report unidirectional laser emission from π-conjugated polymer microcavities with broken symmetry geometries such as spiral and microdisk containing a "line defect," in comparison with plain microdisk cavity having isotropic emission. We found that the laser emission directionality contrast ratio is 8-10 and far field lateral divergence angle is 12°-15° for both broken symmetry geometries, with no significant increase in the laser threshold intensity. Fourier transform analysis of the laser emission spectra shows that unlike microdisks with line defect, the variation of light trajectories in the spiral microcavities leads to less defined laser modes. © 2007 American Institute of Physics.
Keywords
Broken symmetryLaser emission spectra
Lateral divergence angle
Line defect
Conjugated polymers
Emission spectroscopy
Fourier transforms
Laser modes
Laser radiation
Threshold current density
Microcavities