Manipulating Light on a nm-scale
Michal Lipson
School of Electrical and Computer Engineering
Kavli Institute at Cornell
Cornell University
nanophotonics.ece.cornell.edu
Tools to Explore the Nanoscale based on Light Confinement
High Confinement Waveguides
450 nm x 250 nm
SiO2
Light
Si
Intensity in the waveguides can be orders of magnitude higher than
the intensity in the core of single mode optical fiber.
Tools: 1. Mid-IR broadband light source
2. Nanoparticle manipulation
3. Ultra sensitive mass sensor
Light Confining Device
V~2(λ/2n)3
“Slot-Waveguide”
for High Confinement
nC
h
nS
nH
ws
wh
1.0
wh = 180 nm
wh = 180 nm
nH = 3.48
nH = 3.48
Color scale
h = 300 nm
TE-like
mode
nC = nS = 1.46
wS = 50 nm
0
nH
wh
y
z
x
Fabrication of Slot-Waveguide
nC
h
nH
wh
nS
ws
nH
wh
y
z
x
slot
Confinement well below the diffraction limit!
Strong Decrease in Modal Volume
V~2(λ/2n)3
V~0.1(λ/2n)3
Robinson, J. T., Manolatou, C., Chen, L. and Lipson, M., Physical Review Letters, Vol. 95, 2005
Tool1: Mid-IR Broadband Light Source
Visible
Light
Near IR
0.8
1.5 1.6
2
µm
Mid IR
3
Need of Sources
• Spectroscopy, new sources for
communications and sensing.
5
Tool1: Mid-IR Broadband Light Source
•  Highly cascaded nonlinear optical process in dispersionengineered nanowaveguides.
•  Generate ultrabroad frequency combs with low pump powers.
Lipson & Gaeta Groups
Silicon
microresonator
Q > 106
10 µm
single-frequency
laser
frequency comb
comb spectrum
Kavli funding: 2.3-µm pump
laser for mid-IR comb
1.55 µm pump
Tool 2: Nanoparticle Manipulation
n=1.4
SiO2
n=1.45
Silicon
TE Mode E-Field
|Grad of E-Field|
w/ David Erickson
Kavli funding: Joint
Lipson-Erickson
postdoc
Yang, A.H.J., Moore, S.D., Schmidt, B.S., Klug, M., Lipson, M. and Erickson, D.,, Nature, Vol. 457, 71-75, 01 Jan. 2009.
Tool 2: Nanoparticle Manipulation
w/ David Erickson
Yang, A.H.J., Moore, S.D., Schmidt, B.S., Klug, M., Lipson, M. and Erickson, D.,, Nature, Vol. 457, 71-75, 01 Jan. 2009.
Device cross section
Symmetric
Antisymmetric
Attraction
Repulsion
Tool 3: Ultra sensitive Mass Sensor
G. Weiderhecker, M. Lipson, et al, Nature (January, 2010)
Attogram Sensitivity
Tool 3: Ultra Sensitive Mass Sensor
G. Weiderhecker, M. Lipson, et al, Nature (January, 2010)
Conclusions
• High confining nm-scale Waveguides
• Slot Waveguides for guiding in void
beyond the diffraction limit
1. Mid-IR broadband light source
2. Nanoparticle manipulation
3. Ultra sensitive mass sensor
10 µm