Access to eBooks is limited to institutions that have purchased
or currently subscribe to the SPIE eBooks program. eBooks are not
available via an individual subscription. SPIE books (print and
digital) may be purchased individually on
Contact your librarian to recommend SPIE eBooks for your organization.
The gate on most plastic optics is on the edge of the element. When the part is ejected from the mold, it is still attached to the runner system. It is then cut from the runner/gate system in a process known as degating. This remaining plastic is called gate vestige.
Online access to SPIE eBooks is limited to subscribing institutions.