Photonic crystals can be fabricated for one, two, or three dimensions. One-dimensional photonic crystals can be made of thin film layers deposited on each other. Two-dimensional ones can be made by photolithography, or by drilling holes in a suitable substrate. Fabrication methods for three-dimensional ones include drilling under different angles, stacking multiple 2-D layers on top of each other, direct laser writing, or, for example, instigating self-assembly of spheres in a matrix and dissolving the spheres.
Photonic crystals can, in principle, find uses wherever light must be manipulated. For example, dielectric mirrors are one-dimensional photonic crystals which can produce ultra-high reflectivity mirrors at a specified wavelength. Two-dimensional photonic crystals called photonic-crystal fibers are used for fiber-optic communication, among other applications. Three-dimensional crystals may one day be used in optical computers, and could lead to more efficient photovoltaic cells.[3]
Although the energy of light (and all electromagnetic radiation) is quantized in units called photons, the analysis of photonic crystals requires only classical physics. "Photonic" in the name is a reference to photonics, a modern designation for the study of light (optics) and optical engineering. Indeed, the first research into what we now call photonic crystals may have been as early as 1887 when the English physicist Lord Rayleigh experimented with periodic multi-layer dielectric stacks, showing they can effect a photonic band-gap in one dimension. Research interest grew with work in 1987 by Eli Yablonovitch and Sajeev John on periodic optical structures with more than one dimension—now called photonic crystals.Photonic crystals can be fabricated for one, two, or three dimensions. One-dimensional photonic crystals can be made of thin film layers deposited on each other. Two-dimensional ones can be made by photolithography, or by drilling holes in a suitable substrate. Fabrication methods for three-dimensional ones include drilling under different angles, stacking multiple 2-D layers on top of each other, direct laser writing, or, for example, instigating self-assembly of spheres in a matrix and dissolving the spheres.
Photonic crystals can, in principle, find uses wherever light must be manipulated. For example, dielectric mirrors are one-dimensional photonic crystals which can produce ultra-high reflectivity mirrors at a specified wavelength. Two-dimensional photonic crystals called photonic-crystal fibers are used for fiber-optic communication, among other applications. Three-dimensional crystals may one day be used in optical computers, and could lead to more efficient photovoltaic cells.[3]
Although the energy of light (and all electromagnetic radiation) is quantized in units called photons, the analysis of photonic crystals requires only classical physics. "Photonic" in the name is a reference to photonics, a modern designation for the study of light
3. Planar antiresonant reflecting optical
(ARROW) waveguides, SiN/SiO2 (2.1/1.46)
D. Yin et al. 14 June 2004 / Vol. 12, No. 12 /
OPTICS EXPRESS 2710
dc~3.7
mm
12mm
Sensor applications - putting the
light where the analyte (gas) is
4. Tunable multichannel optical filter based on silicon
photonic band gap materials actuation
Y. Yi Et Al., Applied Physics Letters Volume 81, Number 22 25 November 2002
Si
SiO2
Tuneable air gap
Membrane
PBG
Excitation of a defect
mode in the air gap
Elastic deformation of a
membrane by applying voltage
5. Coupling to PC components from
conventional WG and fibers
6. Coupling to photonic crystals from conventional WG
and fibers
Evanescent field coupling
Fiber mode
PCWG mode
TM-like gap
0
0.1
0.2
0.3
0.4
0.5
0.6
frequency
(c/a)
even (TE-like) bands
odd (TM-like) bands
G X M G
( e= 12, r=0.2 a, h=2 a)
Evanescent field,
and direct coupling,
fiber - PCWG
Extended field
coupling, external
beam - PCWG light cone
Extended field coupling
External
focused
beam
Direct coupling
Fiber mode PCWG mode
7. Adiabatic theorem and continuous coupled-mode theory
for efficient taper transitions in photonic crystals
S.G. Johnson et al. PHYSICAL REVIEW E 66, 066608 2002
Butt coupled waveguide and a 2D Pxtal
Wrong taper,
tapered PC mirror
has a PBG at the
WG transmission
frequency
Correct taper, an
“unzipping” PC
Mirror
8. Design of photonic crystal waveguides for evanescent
coupling to optical fiber tapers and integration with
high-Q cavities
Barclay et al., J. Opt. Soc. Am. B/Vol. 20, No. 11/November 2003
Point where fiber mode is phase
matched with a PC WG mode
9. Coupling between a point-defect cavity and a line-
defect waveguide in three-dimensional photonic crystal
M. Okano et al., PHYSICAL REVIEW B 68, 235110 ~2003!
Line defect (removed rod) and
a point defect are designed to
operate at a common frequency
of interest
Position of a waveguide
has to be chosen
accordingly as to
guarantee a high quality
factor of the WG –
resonator system
11. Ultracompact high-efficiency polarizing beam splitter with a
hybrid photonic crystal and conventional waveguide structure
S. Kim et al., OPTICS LETTERS / Vol. 28, No. 23 / December 1, 2003
Ez(TM)
No phase matching
between an incident
WG mode and an
extended PC mode.
Hz(TE)
Incident WG mode is
phase matched to an
an extended PC mode
+ Brewster angle
Constant
frequency
contours
kin
kparallel
12. Aperiodic nanophotonic design - do we really
need a PC to stay cool
I.L. Gheorma Et Al., Journal Of Applied Physics Volume 95, Number 3 1 February 2004
PC’s can be designed to
refract the beam in a
complex way
Aperiodically positioned
scatterers can do the same
job even better
13. Resonant leaky modes above the cladding light
line. Lasing.
TE-like gap
even (TE-like) bands
odd (TM-like) bands
G M K G
( e= 12, r=0.3 a, h=0.5 a)
light cone
Resonant leaky
modes above
the light line
Truly guided
modes below
the light line
14. Waveguide tapers and waveguide bends in AlGaAs-
based two-dimensional photonic crystals (e-beam)
Dinu et al. Appl. Phys. Lett., Vol. 83, No. 22, 1 December 2003
ecore=3.4
2mm
theory
exp
quantum dot with a broad band emission
HeNe Propagation in resonant
modes above
the light line
exp theory
PBG
15. Laser action from two-dimensional distributed feedback
in photonic crystals
(laser dye in organic layer, core)
(cladding)
M. Meier et al., Applied Physics Letters
Volume 74, Number 1 4 January 1999
Symmetry points of zero group velocity
due to band splitting. Standing waves -
distributed feed back lasing
Two guided
modes in a slab
Lasing at M point
light cone
16. Evidence for bandedge lasing in a two-dimensional photonic
bandgap polymer laser
N. Moll Et Al., Applied Physics Letters Volume 80, Number 5 4 February 2002
TE
TM
(organic gain media, core)
clad
resonant leaky
modes above
the light line
18. Two-dimensional coupled photonic crystal resonator arrays
H. Altug and J. Vuckovic, Applied Physics Letters, Volume 84, Number 2 12 January 2004
Very flat bands - considerably reduced
group velocity for all directions.
Application in optical delay lines, low-
treshold lasers, non-linear phenomena.
