Generally inorganic compounds shows very high quality factor but consider organic compounds it is too low, is there any reason to explain this.
The organic resonators have smaller refractive index than inorganic resonators, or their perimeters are not as well as inorganic resonators. In addition,mode Q factors may be greatly limited by the vertical radiation loss to the substrate or supported material.
Dear Prof. Yong-Zhen Huang,
Thanks for your answer, I used glass (SiO2) as a substrate I got one Q- value while change substrate by quartz Q- value changes is there any explanation this?
The index of glass is around 1.52, and the index of quartz is around 1.45 (roughly). Prof. Yong-Zhen Huang is right: Assuming that your organic material has an index around 1.6 or more, than you should get probably a larger Q on quartz (the index contrast is larger, which should reduce the loss through the substrate).
Q-factor depends upon numerous parameters when it comes to fabrication. Refractive index contrast one key aspect. Others include fabrication imperfections such as vertical sidewalls and surface finish of the process. High Q-factors have been achieved in Silicon, Silicon Nitride, Aluminum Nitride, etc. but in case of organic material and polymers such high values were not achieved. People mainly consider refractive index contrast as one of the reasons but material properties itself are itself a major challenge. For example, using similar e-beam lithography for fabrication of SU-8 and silicon resonators will result in different surface finish.
In general, more refractive index contrast in good. It means that the core should have more refractive index difference between itself and the cladding. If you make your material platform in a manner that allows this, you can still have good Q-resonators using organic materials.
- Badges
- Science topic
- Similar topics
- Engineering
- Electrical Engineering