Recovery of photodegraded rhodamine 6g in ester-containing polymer matrices.

Self-healing, rhodamine 6g, dye-doped polymers are reported. The amplified spontaneous emission (ASE) photodegrades after repeated exposure to 532 nm laser light at 10 Hz. Recovery of the ASE signal is observed in dye-doped thermoplastic polyurethane and glycol-modified poly(ethylene terephthalate); both polymers contain repeating ester groups in their backbone.

Folding flexible co-extruded all-polymer multilayer distributed feedback films to control lasing.

We report on improved gain and spectral control in co-extruded all-polymer multilayer distributed feedback (DFB) lasers achieved by folding and deliberate modification of the center "defect" layer. Because DFB laser gain is greater at spectral defects inside the reflection band than at the band edges, manipulation of structural defects can be used to alter spectral defects and thereby tune the output wavelength and improve laser efficiency. By experimentally terracing the layer that becomes the center of the fold, we tuned the lasing wavelength across the reflection stop-band (∼25 nm) in controllable, discrete steps.