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The dynamical behavior of broken symmetric coupled cavity lasers is theoretically investigated. The frequency response of this class of lasers is obtained using small signal analysis under direct modulation. Our model predicts a modulation bandwidth enhancement as a broken symmetric laser, operating in the parity-time (PT) symmetry and non-PT symmetry domains. This theoretical prediction is numerically examined in a laser system based on an InGaAs quantum dot platform. Our results clearly show that in these structures, in addition to the injection current, the gain-loss contrast can be used as a new degree of freedom in order to control the characteristic poles of the frequency response function.
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Direct modulation of electrically pumped coupled microring lasers
We demonstrate how the presence of gain-loss contrast between two coupled identical resonators can be used as a new degree of freedom to enhance the modulation frequency response of laser diodes. An electrically pumped microring laser system with a bending radius of 50 μm is fabricated on an InAlGaAs/InP MQW p-i-n structure. The room temperature continuous wave (CW) laser threshold current of the device is 27 mA. By adjusting the ratio between the injection current levels in the two coupled microrings, our experimental results clearly show a bandwidth improvement by up to 1.63 times the fundamental resonant frequency of the individual device. This matches well with our rate equation simulation model.
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- PAR ID:
- 10531207
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Express
- Volume:
- 30
- Issue:
- 2
- ISSN:
- 1094-4087; OPEXFF
- Format(s):
- Medium: X Size: Article No. 1143
- Size(s):
- Article No. 1143
- Sponsoring Org:
- National Science Foundation
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