Double Ring Resonators
In a double ring resonator, two ring waveguides are used instead of one. They may be arranged in series (as shown on the right) or in parallel. When using two ring waveguides in series, the output of the double ring resonator will be in the same direction as the input (albeit with a lateral shift). When the input light meets the resonance condition of the first ring, it will couple into the ring and travel around inside of it. As subsequent loops around the first ring bring the light to the resonance condition of the second ring, the two rings will be coupled together and the light will be passed into the second ring. By the same method, the light will then eventually be transferred into the bus output waveguide. Therefore, in order to transmit light through a double ring resonator system, we will need to satisfy the resonant condition for both rings as follows:
where and are the mode numbers of the first and second ring respectively and they must remain as positive integer numbers. For the light to exit the ring resonator to the output bus waveguide, the wavelength of the light in each ring must be same. That is, for resonance to occur. As such, we get the following equation governing resonance:
Note that both and need to remain integers.
Read more about this topic: Optical Ring Resonators
Famous quotes containing the words double and/or ring:
“Women have acquired equal place to man in society, but the double standard has really never been relinquished; certainly not by men. Modern man’s fear of passivity or of the active woman proves to be as eternal as modern woman’s struggle to come to terms with her femininity.”
—Peter Blos (20th century)
“I started out very quiet and I beat Mr. Turgenev. Then I trained hard and I beat Mr. de Maupassant. I’ve fought two draws with Mr. Stendhal, and I think I had an edge in the last one. But nobody’s going to get me in any ring with Mr. Tolstoy unless I’m crazy or I keep getting better.”
—Ernest Hemingway (1899–1961)