ISO 11807-2 pdf download – lntegrated optics -Vocabulary —Part 2: Terms used in classification.
2.3 Passive elements and chips
2.3.1
slab wavegulde
waveguide which confines the radiation only perpendicular to the substrate
2.3.2
strip waveguide
element which confines the radiation in a two-dimensional cross-sectional area perpendicular to the substrate surface along a one-dimensional path
NOTE In gefleral the core or. in the case of a graded index piofile, the corresponding core area, may be formed as:
embedded channel [see Figure 2a)J or buried channel [see Figure 2bJ:
ridge on a substrate [see Figure 2c)J:
— ridge in a waveguiding layer [see Figure 2d)J or rib on a waveguiding layer [strip-loaded waveguide: see Figure 2e)J.
2.3.3
branch
element which divides an input strip waveguide into multiple output strip waveguides
NOTE Depending on the application, a distinction is made between a divider usually a 1 x M divider and a combiner, usually a N x 1 combiner.
2.3.4
tap
element which couples a given portion of radiation out of a strip waveguide into another waveguide branching out of the side of the original waveguide
2.3.5 V-branch
element which divides the power of a guided radiation wave into two radiation waves, usually of the same power and phase shift
2.3.6
directional coupler
four-port element consisting of a pair of strip waveguides in which the fields are mutually coupled and the input and output ends diverge from one another
NOTE 1 The two waveguides may be closely spaced, intersect, or cross each other at an acute angle.
NOTE 2 The function is based on the principle Of penodic coupling ol radiation by interference. They can be fabricated as either a passive or controllable element. Directional couplers where the waveguides intersect each other (at an acute angle) are also given the designation X-coupler.
2.3.7
3-dB coupler
four-port element which divides the entering power of radiation equally between both output waveguides
2.3.8
Nx M star coupler
element in which the radiant power of N input waveguides is distributed equally amongst M output waveguides
NOTE The star coupler can be configured from networb ed V-branches and/or 3-dB couplers or a multi-mode waveguide section,
2.3.9
waveguide intersection
element consisting of two strip waveguides which intersect one another
NOTE 1 If the angle of intersection is large enough (ideal case 900), then no mutual interference occurs between the guided waves in the individual waveguides.
NOTE 2 If the angle of intersection is small, then coupling occurs (ct. 2.3.6 directional coupler); this element is then referred to as an X-coupler.
2.3.10
waveguide offset
abrupt lateral displacement of the waveguide border which can lead to a disturbance of the propagated radiation, or. at the transition between waveguide sections of different or opposite curvature, can be used to improve field overlapping
2.3.11
taper
waveguide in which the cross section varies along the length of the waveguide, giving rise to either a continuous graded widening or narrowing of the cross section
ISO 11807-2 pdf download – lntegrated optics -Vocabulary —Part 2: Terms used in classification
