Periodic Reporting for period 4 - RENOS (Rare earth doped novel on-chip sources)
Reporting period: 2020-04-01 to 2020-09-30
What is the problem being address?
In RENOS we want to develop compact, low cost, power efficient, tunable lasers and frequency combs spanning large bandwidths, exhibiting excellent output beam characteristics, such as the ones achieved in solid-state sources, and expanding the wavelength ranges of typical solid-state materials. Such devices will greatly benefit application fields such as optical sensing, spectroscopy, metrology and telecommunications.
Why is it important for society?
In our digital society, the demand for bandwidth is ever increasing. Furthermore, we are living in an aging society. A paradigm change from curing to prevention will permit ensuring a good quality of life of the population while maintaining a sustainable healthcare system. Compact and energy efficient on-chip laser sources that can provide a much broader range of frequencies spanning from the visible to the mid-IR will represent a major milestone. Such lasers can find applications in communications, datacoms but also in spectroscopy, metrology and optical sensing.
What are the overall objectives?
In RENOS, we study the generation of novel frequencies and frequency combs by stimulated Raman scattering and four-wave mixing in high-contrast waveguides in rare-earth-doped potassium double tungstates materials (RE:KYW) by exploiting both their excellent optical gain properties as well as their large non-linear index of refraction. Different waveguide structures and devices are investigated as well as their integration with passive integrated photonic platforms to enable the development of complex devices with the aforementioned functionalities.
In RENOS we want to develop compact, low cost, power efficient, tunable lasers and frequency combs spanning large bandwidths, exhibiting excellent output beam characteristics, such as the ones achieved in solid-state sources, and expanding the wavelength ranges of typical solid-state materials. Such devices will greatly benefit application fields such as optical sensing, spectroscopy, metrology and telecommunications.
Why is it important for society?
In our digital society, the demand for bandwidth is ever increasing. Furthermore, we are living in an aging society. A paradigm change from curing to prevention will permit ensuring a good quality of life of the population while maintaining a sustainable healthcare system. Compact and energy efficient on-chip laser sources that can provide a much broader range of frequencies spanning from the visible to the mid-IR will represent a major milestone. Such lasers can find applications in communications, datacoms but also in spectroscopy, metrology and optical sensing.
What are the overall objectives?
In RENOS, we study the generation of novel frequencies and frequency combs by stimulated Raman scattering and four-wave mixing in high-contrast waveguides in rare-earth-doped potassium double tungstates materials (RE:KYW) by exploiting both their excellent optical gain properties as well as their large non-linear index of refraction. Different waveguide structures and devices are investigated as well as their integration with passive integrated photonic platforms to enable the development of complex devices with the aforementioned functionalities.
During the first reporting period, the efforts have been focused on achieving low-loss high refractive index contrast waveguides in KY(WO4)2 (KYW) for the realization of microring/microdisk resonators with the correct dispersion as well as their integration on a SiO2 substrate to develop the KYW-on-insulator platform , in which realize the active devices in the second part of the project. Three main types of waveguides have been investigated:
1. High refractive index waveguides in KYW by bonding followed by lapping and polishing.
2. High refractive index waveguides in KYW by swift carbon ion implantation.
3. Pedestal waveguides and microdisk devices.
4. Dielectric loaded TiO2-KY(WO4)2 hybrid waveguides.
5. Low-loss high refractive index Al2O3 waveguides with anomalous dispersion.
6. SiNOS: Si3N4-on-sapphire integrated photonics platform.
1. High refractive index waveguides in KYW by bonding followed by lapping and polishing.
2. High refractive index waveguides in KYW by swift carbon ion implantation.
3. Pedestal waveguides and microdisk devices.
4. Dielectric loaded TiO2-KY(WO4)2 hybrid waveguides.
5. Low-loss high refractive index Al2O3 waveguides with anomalous dispersion.
6. SiNOS: Si3N4-on-sapphire integrated photonics platform.
- KY(WO4)2 as material for integrated photonics: The results achieved in RENOS advance the state-of-the-art in high-contrast waveguides in KYW. Thin layers of KYW can now be produced with excellent planarity. We understand how to realize step-index waveguides in KYW using swift-ion irradiation. The flexibility given by the preferential etching achieved after irradiation, will permit to develop devices with the desired geometry. Irradiation-induced amorphization and selective wet-etching permits fabricating suspended structures in crytalline KY(WO4)2, which has been demonstrated by the realization of pedestal microdisks. Dielectric loaded waveguide have been developed by depositing a 200 nm thick and 2000 nm wide ridge of TiO2 onto the carbon ion irradiated KY(WO4)2 (9 MeV) leading to hybrid waveguides.
- High refractive index dispersion engineered Al2O3 waveguides: the technologies developed in RENOS permit to deposit thick Al2O3 waveguides, with high refractive index that can be dispersion engineer to exhibit anomalous dispersion. Losses below 0.2dB/cm have been achieved in such thick high confinemnet waveguides.
- SiNOS technology: first proposal of the technology, which holds the promise of thick low-loss Si3N4 waveguides, which can be easily dispersion engineered.
- High refractive index dispersion engineered Al2O3 waveguides: the technologies developed in RENOS permit to deposit thick Al2O3 waveguides, with high refractive index that can be dispersion engineer to exhibit anomalous dispersion. Losses below 0.2dB/cm have been achieved in such thick high confinemnet waveguides.
- SiNOS technology: first proposal of the technology, which holds the promise of thick low-loss Si3N4 waveguides, which can be easily dispersion engineered.