1. The speaker introduce the facilities in the lab and show the background in SOI
2.
3.
4.
5.
(Silicon-on-Insulator) photonics.
Also, he show the pictures of photonic crystals, ultra-compact waveguide devices,
and nano-wave guides.
The industry of motherboard have encountered the major difficulties that lies in
the low birefringence requirements of a DPSK ( Differential Phase Shift Keying )
demodulator.
SOI rib-waveguide technology has been attracted attention due to the
advantages : (1) low-cost fabrication (2) much reduced polarization dependence
(3) the possibility to match silicon waveguide mode
For the information package , it also has such advantages : (1) bit information
encoded in phase (0°/180°) (2) For the balanced detection, it can be refrained to 3
dB easily.
6.
DLI (Delay-Interferometer)
Balanced PD( photon diode )
7. SOI tech also has some challenge need to conquer : low polarization-depend λ
shift.
8. Berlin Group have developed thick SOI that has such advantages : (1) coupling
tolerance (x, y, z) ≧ 0.5μm (2) low polarization dependence (3) low loss for
rib-waveguide.
9. Foe TE,TM mode, it only has pico-meter wavelength shift in the SOI
rib-waveguide.
rib △n + cladding n = small polarization wavelength shift.
10. Wavelength tuning DLI
Position
of
minimum
(pm)
Shift of the
transmission-curve
minima
TM mode
℃
11. The speaker introduces Birefringence-Process uniformity on wafer.
12. SOI rib-waveguide
etch height
△
SOI
h
w
h
12%
x
13.
n
Best-fit △n ≒ 1×10-14
Birefringence
h
14. Waveguide is independent of birefringence from w=3.4μm
15. We can generalize the index in equation from the physical meaning
△n = △ngas + △n stress
16. On the recent research, the group want to reduce the off-shift toward the
perimeter.
17. It usually test system at signals
18.
scope
SOI MZDI
CW
c
laser
(Mach-Zehnde
Pulse carver
r DLI)
demodulator
40 Gb/s DPSK
19.
Polarization & dep. shift
< 5 pm ( < 1GHz )
-log(BER)
Penalty -0.2dB
Receiver Power (dBm)
20. Layout ( SOI DPSK-receiver chip )
RF-IF devices
Balanced
photon diode
Delay
interferometer
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SOI rib-waveguide talk