L. Agazzi

Integrated Al

A combined planar lossless optical amplifier and 1 × 2 power splitter device has been realized in Al2O3:Er3+ on silicon. Net internal gain was measured over a wavelength range of 40 nm across the complete telecom C-band (1525-1565 nm). Calculations predict net gain in a combined amplifier and 1 × 4 power splitter device over the same wavelength range for a total injected pump power as low as 30 mW.

_2

The influence of migration-accelerated energy-transfer upconversion and fast luminescence quenching on the performance of Al₂O₃:Er³⁺ waveguide amplifiers is investigated. Results indicate that the latter has the stronger impact on the amplifier small-signal gain.

O

Erbium-doped aluminum oxide channel waveguides were fabricated on silicon substrates and their characteristics were investigated for Er concentrations ranging from 0.27 to 4.2 × 1020 cm-3. Background losses below 0.3 dB/cm at 1320 nm were measured. For optimum Er concentrations in the range of 1 to 2 × 1020 cm-3, internal net gain was obtained over a wavelength range of 80 nm (1500-1580 nm) and a peak gain of 2.0 dB/cm was measured at 1533 nm. 170 Gbit/s high-speed data amplification was demonstrated in an Al2O3:Er3+ channel waveguide with open eye diagrams and without penalty. A lossless 1×2 power splitter has been realized in Al2O3:Er3+ with net gain over a wavelength range of 40 nm (1525-1565 nm) across the complete telecom C-band.

_3

In this paper we experimentally compare pumping at 977 nm and 1480 nm and the influence on gain in an Al2O3:Er3+ amplifier. We show that significantly higher gain can be achieved when pumping at 977 nm, and a record-high peak gain and gain bandwidth obtains compared to previous results in this material. Al2O3:Er3+ straight channel waveguide amplifiers were fabricated on thermally-oxidized silicon substrates by reactive co-sputtering, standard lithography and reactive ion etching [4]. The amplifiers were ~6-cm-long with a waveguide cross section of 1 Icircfrac14m x 4 Icircfrac14m and an etch depth of ~70 nm. The waveguide dimensions were selected for single-mode propagation at wavelengths of 977 nm and above, good overlap of pump and signal mode profiles (for both 977-nm and 1480-nm pumping) and strong confinement of the propagating pump and signal within the active region.

:Er

Reactively co-sputtered aluminum oxide layers with low background loss and varying Er concentrations have been deposited. Net optical gain of 0.76 dB/cm was obtained for an Er concentration of 0.9times1020 cm-3 in a channel waveguide.

^{3+}

The impact of luminescence quenching on rare-earth-ion doped lasers is investigated, and we show that the expression for the relaxation oscillation frequency needs to be modified to take the quenching properly into account.

Zero-Loss Optical Amplifier and Power Splitter With 40-nm Bandwidth

Co-sputtering and structuring active erbium-doped aluminum oxide waveguides directly on top of processed SOI passive waveguides provides coupling losses of 2.5 dB between active and passive waveguides and a signal enhancement of 7.2 dB.