Recent Progress in Recent Progress in Photonic Crystal Devices - PowerPoint PPT Presentation

Recent Progress in Recent Progress in Photonic Crystal Devices Photonic Crystal Devices Toshihiko Baba Toshihiko Baba baba@ynu.ac.jp Yokohama National University Yokohama National University http://www.dnj.ynu.ac.jp/baba-lab/babalabe.htm CREST, JST CREST, JST http://www.jst.go.jp/kisoken/crest/

Topics PC Nanolaser RT CW lasing in ultrasmall nanocavity Purcell effect and thresholdless behavior Active and passive integration Application to refractive index sensing PC Slow light w aveguide Dispersion-compensated slowlight Zero-dispersion slowlight PC Negative refractive optics Lens and prism effects Application to compact demultiplexer

� � PC Slab 0.7 Light Cone 0.6 Normalized Frequency a / � 0.5 0.4 2 r t PBG 0.3 A thin membrane with airholes 0.2 Light is confined by TIR and PBG effect occurs in the plane J n � 3.5 0.1 X Easily fabricated into SOI, III-V 2 r / a � 0.572 TE-like Pol. with < 5nm roughness t / a � 0.762 0 X J Widely applied for lasers, waveguides, Projected Wave Vector k || dense photonic integration, etc.

Topics PC Nanolaser RT CW lasing in ultrasmall nanocavity Purcell effect and thresholdless behavior Active and passive integration Application to refractive index sensing PC Slow light w aveguide Dispersion-compensated slowlight Zero-dispersion slowlight PC Negative refractive optics Lens and prism effects Application to compact demultiplexer

Point hift PC anolaser anolaser consisting of only two point shift o a i et al EL 41 RT CW lasing first achieved in nanolaser o a i et al OE 15 P eff W RT ntensity Linear a u div CW � � d d � ntensity W Wavelength � m W ffective Pump Power P eff nm � n evaluated World s smallest V m abricated by CP o a i et al APL 88 de et al JJAP 45 L

� Purcell ffect in PC anocavity aba et al APL 85 o a i et al OE 15 rate enhanced by factor x � enhancement expected for various materials including i etc � r � � n V m �� Thresholdless lasing expected �� Cavity linewidth or RT P irr P th homog broadening RT ormali ed ntensity Wafer PC w o cavity Point-shift nanocavity � � mode � m Time ns

Active Passive- ntegrated PC lab Watanabe and aba EL 42 OE 16 nm PC laser and waveguide integrated by butt oint C D regrowth process P eff mW Detected utput Power mW mW div d ntensity d η nm Air Clad RT Pulsed λ µ m PC lab ffective Pump Power P eff mW Air Clad η d estimated for total output Active Passive

� � ntegration of PC anolaser with Waveguide o a i et al APL 2 Laser Coupling of laser and waveguide enhanced by optimi ing distance and direction W W μ m Detected Power by iber Active Passive η diff P th W RT Pulsed ffective Pump Power P eff W a u

� witching ehavior by Resonant Pumping o a i et al APL 2 or Pump or Laser RT CW P irr mW div ntensity Linear a u a u λ pump λ lase d ntensity Wavelength div λ laser λ pump d Pump Wavelength μ m rradiated Power P irr mW ntensity Active λ pump Active Passive Passive Wavelength μ m fficient selective excitation of nanocavity Applicable to wavelength converter bistable λ laser device etc

ndex ensitivity in PC anolaser n env ormali ed ntensity a u m Lasing Wavelength � ax ensitivity nm R pm nvironmental ndex n env Wavelength nm pectral W pm Resolition limit ensitivity of nm R - R Potential detection limit of

ndex ensing using anolaser Array ita et al TuC P- Laser Array Large ndex sensitivity of nm Δ n pectrometer-less sensing from P λ λ using laser array and P λ λ P Cutoff � m Air n m m Air Air-Dissolved PA Air-Dissolved div n ethanol n ethanol d ethanol w o n P ntensity thanol n w PA P n m Wavelength � m

Topics PC Nanolaser RT CW lasing in ultrasmall nanocavity Purcell effect and thresholdless behavior Active and passive integration Application to refractive index sensing PC Slow light w aveguide Dispersion-compensated slowlight Zero-dispersion slowlight PC Negative refractive optics Lens and prism effects Application to compact demultiplexer

PC low Light Waveguide after aba et al EL 5 Photonic andedge Transmission asy fabrication on wafer etc div Lossless guided mode exhibiting slow light at bandedge with d narrow bandwidth and large D Channel rom -P roup ndex n g resonance i rom modulation phase shift Air m i Wavelength � m

Dispersion- ree Widband low Light Dispersion-Compensated Zero-Dispersion low Light low Light L LD Low elocity Low Dispersion ω ω k k patially dispersed patially compressed

� Smooth Delay by Coupled Waveguides (Mori and Baba, Opt. Express 13 , 9398 (2005)) 0.29 Normalized Frequency � a /2 � c 0.25 a 0.28 0.27 0.26 0.3 0.4 0.5 Wave Number k [2 � / a ] k

Dispersion-Compensated low Light in PCCW awasa i ori and aba OE 15 μ m ranch Confluence Coupled Waveguide utput nput W W μ m L μ m μ m � n g n g ven Wavelength μ m π dd n g 55, Δλ nm Wavelength μ m

ffective Delay in low Light Pulse Lensed D A iber D A ode-Loc ed Auto- PCCW iber Laser correlator Δ echanical Delay Time Δ ps roup ndex n g ntensity a u ps Delay Time Δ ps Wavelength λ μ m

Dispersion- ree Widband low Light Dispersion-Compensated Zero-Dispersion low Light low Light L LD Low elocity Low Dispersion ω ω patially dispersed patially compressed

L LD Characteristics in PC Waveguides a ai aba et al EEE LEO Ann Th - - patented in Air Light Cone traight and /2 ω /2π lab ode μ m [2π/

bservation of L LD Characteristics ubo ori and aba OL Transmission div d Calc n g Calc π ω /2π ω /2π ω /2π

Delay- andwidth Relation of lowlight ms b b i i t t Atomic Target for μ s b P Router i t Conversion Conversi Target of Dispersion Dispersi This tudy Photonic Delay Δ ns m -Ring b PC Cavity i t PC-W TT yoto TT PC-W PC-W yoto rillouin D ps P b i t Raman fs T Bandwidth Δ

Topics PC Nanolaser RT CW lasing in ultrasmall nanocavity Purcell effect and thresholdless behavior Active and passive integration Application to refractive index sensing PC Slow light w aveguide Dispersion-compensated slowlight Zero-dispersion slowlight PC Negative refractive optics Lens and prism effects Application to compact demultiplexer

Functions Predicted from Dispersion Surfaces (after Kosaka et al., PRB 58 , 10096 (1998)) 1 2 3 0.53 0.56 0.2 Isotropic 0.54 0.6 Propagation 0.1 0.55 0.64 Super- Collimation 4 5 6 0.74 0.74 0.8 0.76 0.72 0.82 0.72 0.7 0.7 Slow Super Super light prism lens

Negative Refraction by Optimized Interfaces (Baba et al., Opt. Express 12 (2004) 4608) � 20 100% 100% ??% 87% � 20 0.275 0.281 0.287 0.293 0.299 a / � =

bservation of egative Refraction atsumoto et al APL 1 nput μ m W Plot xperiment Line DTD i lab μ m m m μ μ PC Deflection Angle θ m μ μ m λ μ m i lab PC θ Wavelength λ μ m

Light Focusing in PC Superlens (Matsumoto, et al. OL 31, 2776 (2006)) � = 1.305 μm 0.5 μm 0 5 L [ � m] 10 PC slab superlens Intensity [a.u.] 15 3 2 1 0 1 Intensity [a.u.] 2.0 � m 0 -10 0 10 Position [ � m]

Unique Focusing of PC Superlens Dispersion Surface Refractive Lens S S a / � = 0.295 Super- Lens k in Real image formation by flat lens (virtual image by curved lens) Compact total system due to very short focal length Applications to compact parallel optical coupler, demultiplexer, image system, etc.

� � � Applications of uperlens Parallel optical coupler Compact demultiplexer atsumoto et al EL W atsumoto et al OE 1 �฀ � m llustration �฀ � in PC superprism � m xperimental � m P ntensity a u PC PC superlens Position � m

uperprism and uperlens Demultiplexer atsumoto et al APL 1 nput Waveguide λ nm PC uperprism utput ntensity a u PC uperlens utput Waveguide μ m Wavelength μ m

Topics PC Nanolaser RT CW lasing in ultrasmall nanocavity Purcell effect and thresholdless behavior Active and passive integration Application to refractive index sensing PC Slow light w aveguide Dispersion-compensated slowlight Zero-dispersion slowlight PC Negative refractive optics Lens and prism effects Application to compact demultiplexer