Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5448967 | Optics Communications | 2018 | 6 Pages |
Abstract
In this paper a theoretical derivation of unloaded and loaded Q-factor of delay-line cavities, such as optical fiber delay-lines, and delay-line based oscillators, such as optoelectronic oscillators (OEOs), is presented based on three approaches: (I) second-order resonator approximation, (II) linear time-invariant phase-space model and (III) energy approach. Theoretical expressions for unloaded and loaded Q-factor of delay-line based cavities and oscillators are derived. We show that the Q-factor of a delay-line based cavity is a function of its round-trip time that is not equal to the energy decay-time of usual microwave or optical resonators. Hence, the behavior of the Q-factor of a delay-line based cavity will not be the same as that of the usual resonators. We show that the loaded Q-factor of a delay-line cavity is greater than its unloaded Q-factor!, besides we show that the Q-factor of a lossy delay-line cavity is the same as that of the lossless one! (in contrast to the behavior of the usual resonators). We also show that the Q-factor of a delay-line based oscillator is proportional to the half of the round-trip time of its delay line while the Q-factor of an oscillator based on a usual resonator is proportional to the energy decay time of its resonator.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
S. Esmail Hosseini, Azadeh Karimi, Sajad Jahanbakht,