Final Report on LDRD Project: Heterogeneous Integration of Optoelectronic Arrays and Microelectronics Page: 46 of 97
This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
SPIE Vol. 4942 (VCSELs and Optical Interconnects) (2002) Paper 37
f Iff
(a) (b) (C)
Figure 4 (a) Wire-bonded 8x8 VCSEL array with ~0.5 mA threshold and 3.5+ mW maximum output singlemode power. (b) All
VCSELs powered up. (c) Wire-bonded GaAs MESFET IC photoreceiver with large 50 microns square MSM photodetectors.
and each cluster would carry almost equal amount of light from each separate VCSEL [31]. In addition, however, at
least four kinds of input-output optics have been used for bringing VCSEL light into the FIG and for taking the output
light on to the photodetector. These are: linear fiber tapers [30], large (macro- and mini-) lens-based focusing optics
[30,32,35,36], microlens-arrays [34] and separate fibers attached to the output facet of the FIG [34]. Like FSOI, FIG-
based optical interconnects that depend on large lens assemblies are bulky and may suffer from both high cost and long-
term thermal-mechanical instability. Simplicity dictates butt coupling or short distance coupling with or without
microlens arrays.
Fiber image guide based links have been demonstrated at up to 1 Gbis [31,35] and 3 GHz [35], but a detailed
understanding of link parameters and design limits are unavailable, Gaussian beam input coupling analyses [39,40]
have reported first order estimation of the coupling efficiency between laser emissions and FIG input facets,
Our work identifies additional VCSEL-FIG coupling issues and FIG parameters of relevance. These are categorized but
only some are addressed in this paper.
EXPERIMENTAL & SIMULATION DETAILS
The Fiber Image Guide (FIG)2- magig F ber Gude Fiber (V n::'
on x-y-z Stage
LAir
so "
Figure 5 VCSEL-array-FIG experimental setup.Fiber image guides of 20-cm length and of numerical apertures
0.25, 0.55 and 1.00 were used. These numerical apertures
correspond to core and clad refractive indices respectively of
[1.58, 1.56], [1.58, 1.486] and [1.80, 1.486] (Table 1). The -1.8
mm hexagonal cross-section FIGs consists of 15379 fibers with
9.1- rn core at a 13.5- gm pitch, with 2 m thick clad. The space
between the individual fibers is filled with acid soluble glass
(ASG) with a 1.61 refractive index. Schott Fiber Optics
manufactured them by using a three-stage fiber pulling technique
shown in Fig. 2. At the end of the production process, the long,
solid rod with embedded fibers is optically polished to produce
the input and the output facets. The two ends are then dipped in
an etch mask polymer to few to -10 mm in length. The entire rod
is dipped in an acid that dissolves the ASG from the long, central
part. The fibers are therefore embedded in ASG at the two ends
but have air between them in the central part that gives the FIG
its flexibility. The polymer is then removed and the FIG encased
in a protective, but flexible, shield for use. For applications with
known connector types, the polished ends are connectorized.4
Upcoming Pages
Here’s what’s next.
Search Inside
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Geib, Kent M.; Serkland, Darwin K.; Choquette, K. D.; Allerman, Andrew A.; Peake, Gregory M.; Hargett, Terry et al. Final Report on LDRD Project: Heterogeneous Integration of Optoelectronic Arrays and Microelectronics, report, February 1, 2003; Albuquerque, New Mexico. (https://digital.library.unt.edu/ark:/67531/metadc734637/m1/46/: accessed March 28, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.