Active metal strip hybrid plasmonic waveguide with low critical material gain

An active metal strip hybrid plasmonic waveguide (MSHPW) using gain materials as loss compensation is proposed with an extremely simple fabrication procedure. Gain materials are introduced either in the low-index layer or in the high-index layer of MSHPW. The effects of waveguide dimensions and material gain coefficients on loss compensation are analyzed at the communication wavelength. For one configuration presented here, a critical material gain as low as 3.8cm(-1) is sufficient for fully compensation of the loss when using a high-index gain material. The active MSHPW with low critical material gain opens up opportunities for practical plasmonic devices in active applications such as amplifiers, sources, and modulators.