Skip to main content
European Commission logo print header

Photonic integrated devices in activated amorphous and crystalline oxides

Exploitable results

Important progress to the worldwide state of the art in pulsed laser deposition (PLD) growth has been achieved by the homo-epitaxial growth of rare-earth-ion doped sesquioxide thin films. This research highlight has directly contributed to the first demonstration of lasing in Nd- and Yb-doped (Gd,Lu)2O3 channel waveguides. Output powers up to 12 mW and pump thresholds as low as 1 mW have been obtained. Some key parameters (linewidth, output stability, and polarisation) for the envisaged space applications (satellite clocks and communication) still need to be measured. Although the realisation of fully integrated on-chip lasers applying this novel materials class will require further development in future research collaborations, we expect a high impact and good market perspective of this integrated laser due to the following reasons: (a) linewidth and high-power performance of dielectric crystalline lasers is generally significantly better as compared to their semiconductor counterparts, and (b) the fabrication cost of an integrated version is calculated to be ~10x lower as compared to bulky solutions. A reliable, wafer-scale amorphous Er-doped Al2O3 waveguide technology yielding excellent optical properties has been developed and implemented in the 'Photonic integrated devices in activated amorphous and crystalline oxides' (PI-oxide) project. Gain measurements on channel waveguides with non-optimized length resulted in 2 dB/cm net gain, 80 nm gain bandwidth and over 3.5 dB amplification throughout the C-band. Calculations on amplifier length optimisation predict future gain values above 18 dB throughout the C-band, which is comparable to currently available amplifier solutions. By demonstrating high-speed amplifier performance at 40 GBit/s, the high potential of the novel erbium-doped amorphous aluminum oxide technology has been shown. In order to finalise the development of stand-alone highspeed amplifiers based on the new technology the following steps need to be addressed in an end-user driven project: (a) amplifier design optimisation with respect to device length (max. gain), polarisation-dependent loss, fiber-to-chip coupling, and chip foot-print minimisation, (b) full characterisation including parameters like noise figure, gain ripple, polarisation dependent loss and gain, and bitrates up to 160 GBit/s, and (c) development of assembly / packaging. According to the cost price calculation examples performed in the outline business case fully packaged high-speed amplifier devices are expected to become available at approximately EUR 50 and EUR 15 for five-point connections (optical backbone) and point-to-point connections (business LAN), respectively. Besides the realisation of stand-alone devices, as focused on throughout the PI-oxide project, the Si-compatibility of the developed Al2O3 technology is expected to add particularly to the attractiveness and lead to a high impact upon future research on integration with Si-photonics. Monolithic integration of amplifier components on multifunctional optical chips will not face any competition from fiber amplifiers or stand-alone waveguide amplifiers. Further achievements include the development of software tools to support the design process of new devices in the technologies described above. The realisation of the active materials modules, their combination with integrated optical design methods and S-matrix calculation tools substantially expanded Phoenix software portfolio. Besides the direct contribution to the PI-oxide project, future projects on integrated optical amplifiers and lasers as well as Phoenix software market share will benefit from these results. The demonstration of amorphous Al2O3 deposition and the feasibility for in-situ local deposition have shown the potential for future mass-fabrication facilities based on HV-CVD technology. Fabrication of sesquioxide thin films such as Y2O3 and the controlled incorporation of rare-earth ions into the growing films will, however, require further fundamental research. The realisation of ready-to-sell manufacturing equipment by Vacotec is considered to be an important step towards the commercialisation of this novel technique. In conclusion, the research project PI-oxide, funded in part by the European Union, has delivered several breakthroughs in the materials and technology development for the fabrication of optically active devices. First results on integrated on-chip light generation and high-speed amplification have been successfully demonstrated. The generated results form a solid basis for the future research collaboration between the partners of the PI-oxide consortium, and have enabled several follow-up R&D projects, in which together with industrial end-users integrated amplifier and laser products will be developed and introduced to the market.

Searching for OpenAIRE data...

There was an error trying to search data from OpenAIRE

No results available