Gain and Emission Cross Section Analysis of Wavelength-Tunable Si-nc Incorporated Si-Rich ${\rm SiO}_{\rm x}$ Waveguide Amplifier

Multi wavelength strip-loaded waveguide amplifiers fabricated by growing Si-nanocrystal (Si-nc) incorporated Si-rich SiO_x with detuning N₂O/SiH₄ fluence ratio and RF plasma power are demonstrated, which show blue, yellow, and red multicolor amplified-spontaneous-emission (ASE) with gain coefficients of 157, 62, and 85.6 cm^-1, and the corresponding products of Si-ncs emission cross section and Si-ncs radiative lifetime are 2.34 × 10^-21, 1.78 × 10^-21, and 1.28 × 10^-21cm²-s, respectively, as deduced from the maximum gain-length product. Combining the time-resolved photoluminescence with the maximum gain-length product result, the Si-ncs cross section/carrier lifetime for the blue-, yellow-, and red-ASE SiO_x: Si-nc samples are 1.37 × 10^-14/0.17, 6.84 × 10^-16/2.6, and 0.64 × 10^-16/20 (cm²/μs) , respectively. The high-gain blue-ASE sample exhibits a shorter saturation length of 0.25 mm with the highest loss coefficient due to scattering loss by Si-ncs of the highest density. The gain saturation of the strip-loaded SiO_x:Si-nc waveguide is discussed.