Published online by Cambridge University Press: 25 January 2011
Fields in channel waveguides are confined to the vicinity of the core within a few μm in both the lateral and the depth directions. There are two main advantages of the lateral confinement of channel guided-wave modes:
(1) The RF electric field required to obtain an electro-optical effect such as electro-optic change of index or electro-absorption needs only to exist in a small region around the core. The required electric field in a small region can be achieved with just a moderate RF voltage applied to the electrodes. Furthermore, when the electrodes are fabricated parallel to the channel waveguides, the electro-optical change of index or electro-absorption produced by a propagating RF signal can be synchronized with the propagation of the guided wave in a traveling wave interaction as discussed in Chapter 4. Thus the electro-optical modulation at high frequencies may be carried out effectively.
(2) Most optoelectronic devices are eventually connected to single mode optical fibers. The optical field pattern of the channel waveguides can be designed such that it matches well with the field pattern of single mode optical fibers or tapered fibers, providing high efficiency transmission of optical power to and from the low loss single mode fibers.
Traditionally, guided-wave devices have been discussed in the literature according to the type of optical interactions they utilize, such as directional coupling or electro-absorption.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.