Slow pulses in disordered photonic-crystal waveguides

Area of Science:

• Photonics
• Waveguide Optics
• Solid State Physics

Background:

• Photonic-crystal waveguides (PhCW) offer unique light manipulation capabilities.
• Slow-light phenomena in PhCWs are crucial for integrated optics but susceptible to disorder.
• Understanding pulse transport in disordered PhCWs is essential for device design.

Purpose of the Study:

• To systematically investigate the transport of slow-light pulses in single-mode PhCWs with realistic disorder.
• To determine the impact of group velocity on pulse broadening and distortion in PhCWs.
• To establish practical limitations for PhCW group indices based on pulse quality.

Main Methods:

• Utilized a 3D fully-vectorial coupled Bloch-mode method for simulation.
• Modeled realistic disorder within the PhCW structure.
• Analyzed pulse broadening, distortion, and delay as a function of group velocity and waveguide length.

Main Results:

• Group velocity significantly impacts pulse broadening and distortion in the intermediate disorder regime (3 dB attenuation).
• Practical application of PhCWs is limited to group indices below approximately 50.
• At lower group velocities, additional pulse delay occurs, rendering group velocity an unreliable metric.

Conclusions:

• Disorder in PhCWs critically affects slow-light pulse transport, especially at higher group indices.
• The group velocity's influence necessitates careful consideration for PhCW applications requiring high group indices.
• Further research may explore mitigation strategies for disorder-induced pulse degradation in PhCWs.