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.

An Er/Yb silicate strip loaded waveguide was fabricated for optical amplification purpose. A 2.4-lm-wide SiO 2 strip was deposited on top of the Er/Yb silicate active layer. Experiment data showed a 5.5 dB signal enhancement in a 7.8-mm-long waveguide pumped by a laser of 372 mW at 1480 nm. The signal is not saturated and can be further enhanced by increasing pumping power and decreasing waveguide loss. The strong red light emission at 660 nm was also observed due to excited state absorption and Yb 3þ participated energy transfer upconversion processes.

Extraordinary infrared photoluminescence efficiency was found for Er 2 SiO 5 film by optimizing the composition of Yb additions on SiO 2 / Si substrates. Above two orders of magnitude enhanced 1.53 m Er 3+ photoluminescence for the Er 0.1 Yb 1.9 SiO 5 film on SiO 2 / Si substrate was obtained by pumping at 980 nm compared with pure Er 2 SiO 5 film on Si substrate at 654 nm. All Er ions for Er 0.1 Yb 1.9 SiO 5 film are optically active. The decreased nonradiative transient rate leads to extraordinary photoluminescence efficiency in the Er 0.1 Yb 1.9 SiO 5 film. It indicated that the Er 0.1 Yb 1.9 SiO 5 film is the sought candidate material for compact waveguide amplifiers and emitters in silicon photonics integration.

Active slot waveguides were fabricated by embedding low-index Er/Yb silicate material in high-index silicon. A 1.7 dB signal enhancement at 1.53 µm in a 6 mm-long slot waveguide was observed through 1476 nm pumping. The peak Er emission cross-section is determined as 7.53×10(-21)  cm2 and the excited Er ion fraction is 0.17. Our experiment shows that the defects in upper c-Si of Si-on-insulator (SOI) and deposited α-Si distorts photoluminescence spectrum and prevents further optical amplification. This negative effect can be partly corrected through annealing treatment, which allows better propagation of the pump light, therefore, stronger excitation in the sandwiched Er/Yb silicate. The defects also affect the 1.53 µm decay curve and are the dominant lifetime reduction mechanism in the active slot waveguide.