Polariton transistor

Polariton transistor: towards all-optical logics

Fluids of polaritons for optical logics: the polariton transistor

All-optical devices, a small overview

Daniele Sanvitto

D. Ballarini, M. De Giorgi, G. Gigli

Polariton, bistability and switches

ESF Workshop - MIFP 2012 D. Sanvitto

E. Cancellieri, E. Giacobino, A. Bramati

F. Marchetti, C. Tejedor

M. H. Szymanska

Work done in collaboration with


The transistor…


Address

Control

Output

Characteristics

Switching power

Area:

Low cost

50 x 50 nm

CMOS X 4 10-2 µm2

100 aJ

Operation speed

The transistor…

best performance 50 GHz


Almeida et al Nature, 431 1081 (2004)

“All-optical control of light in a silicon chip”

Transmission can be changed in 500 ps with pulse energies of 25 pJ

Time limited by carrier decay

Optical devices…


Belotti et al. Opt. Express 18, 1450 (2010)

“All-optical switching in SOI photonic wire nano-cavities”

Switching power of 0.1 pJ in an area of 5 µm2 ns speed modulation

Optimised V/Q2 for low power switching

Optical devices…


Nozaki et al. Nat. Phot. 4, 477 (2010)

“Sub-femtojoule all-optical switching using a photonic-crystal nanocavity”

Switching power of 0.5 fJ with an operative area of many µm2 speed modulation in tenths of ps

Using of relatively small Q but very small V

Optical devices…


Ferrera et al. Nat. Comm. 1, 29 (2010)

“On-chip CMOS-compativle all-optical integrator”

Very high Q 106 but fast switch time 8 ps

Ring cavity for integration operations

Optical devices…


Switching energy of 0.3 fJ with a pulse of 1 ns

“Low-switching-energy and high-repetition-frequency all-optical flip-flop operations of a polarization bistable vertical-cavity surface-emitting laser”

Mori et al. App. Phys. Lett. 88, 101102 (2006)

Optical devices…


What are the possibilities to use polariton fluids as switchers and amplifiers?

Polariton fluids for optical logics…

Inputs


GaAs/AlGaAs based microcavity structure

Polaritons in semiconductor microcavities

h+

e-

+

Top DBR

Bottom DBR

Cavity

-3 -2 -1 0 1 2 3

1.526

1.528

1.530

1.532

En

erg

y (

eV

)

k (m-1)

Light

Matter Polaritons

Advantages

Short lifetimes and very fast propagation speeds

Strong non-linearities

Easy mode tuning

Possibility of operations with coherent particles

Integration with present semiconductor tecnology

bistability, OPO, TOPA, gain


D. M. Whittaker, Phys. Rev. B 71, 115301 (2005) See also Gippius et al., Europhys. Lett. 67, 997 (2004)

Baas et al. Phys. Rev. A 69, 023809 (2004)

Towards a polariton logic

Bistability in polariton microcavities


Liew, et al. Phys Rev. Lett. 101, 016402 (2008)

“Optical circuits based on polariton neurons…”



Paraiso et al. Nat. Mat. 9, 655 (2010)

Independent bistable, or multistable behaviour for different polariton spin populations



Amo et al. Nat. Phot. 4, 361 (2010)

Polariton switch using two degenerate beams: Switching energies in fJ range + propagation



Degenerate two pumps experiment showing an AND gate behaviour

Leyder et al. Phys. Rev. Lett 99, 196402 (2007)



- Complete logic functionality (NOR or NAND gate)

- Cascadability – the output of one stage must be in the correct form to drive the input of the

next stage (interchangeability of input and output)

- Fan Out – the output of one stage must be sufficient to drive the input of at least two

subsequent stages (fan out or signal gain of at least two)

- Logic-level restoration

- Input-output isolation

Criteria for practical optical logic:


Low power On resonance High power

On/Off for a resonant pump


Cancellieri et al. Phys. Rev. Lett. 108, 065301 (2012) See also Phys. Rev. B 83, 214507 (2011)

Interaction and behaviour of two non degenerate fluids in the microcavity

Influence of two fluids on each other superfluidity/supersonicity


-5 -4 -3 -2 -1 0 1 2 3 4 5

1,479

1,480

1,481

1,482

1,483

1,484

1,485

1,486

Energ

y (e

V)

k// (m

-1)

0 20 40 60 80 100 120 140 160 180 200 220-0,1

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,0

1,1

S2

No

rmaliz

ed E

mis

sio

n In

tensity

(a.u

.)

Input Power

0 20 40 60 80 100 120 140 160 180 200 220-0,1

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,0

1,1

S1

Norm

aliz

ed E

mis

sio

n In

tensity

(a.u

.)

Input Power

Polariton bistability with two fluids

Bistability of two independent pump states

P2

P1


Polariton transistor



Address Control

Independent control and address states



Effect of the control on the address switching



The intrinsic power to switch polariton is a few atto Joule

Fixing the address power the control undergoes a strong gain


Changes of the control gain with detuning of the address from the LPB



Far field

A

B C

A B

B+C A

A

B C

Below threshold

Above threshold

Real space

Two addresses A and B, one control C

Two polariton transistors in a cascade experiment

30 µm


0 10 20 30 40 50

Pump power (mW)

Sig

nal E

mis

sio

n

How fast is the transition on/off and off/on ?

-3 -2 -1 0 1 2 3 4

1,485

1,490

1,495

1,500

1,505

1,510

Energ

y (

eV

)

kx (m

-1)

On

Off


-200 0 200 400 600 800 1000 1200 1400 1600

Time (ps)

Pcw

= 30 mW

Ppulsed

= 41 mW

Inte

nsi

ty E

mis

sion (

a.u.

)

-200 0 200 400 600 800 1000 1200 1400 1600

Inte

nsity

Em

issio

n (

a.u

.)

Time (ps)

Pcw

= 3.3 mW

Ppulsed

= 6 mW

(d)

(c)

Streak image Streak image

The state is off and the pulse arriving it pushes it to resonance

The state is on and the arrival of the pulse reduces the emission down

How fast is the transition on/off and off/on ?


-200 0 200 400 600 800 1000 1200 1400 1600

0

100

200

300

400

500

600

700

K

1 S

ign

al E

mis

sio

n In

tesity (

a. u

.)

Time (ps)

P1mW

P2.5mW

P3.3mW

P4mW

Effect of pump power on the intensity of the on signal


-200 0 200 400 600 800 1000120014001600

300

600

900

0 mW

6 mW

41 mW

54 mW

Sig

nal E

mis

sio

n Inte

nsity (

arb

. uni.)

Time (ps)

Effect of pump power on the intensity of the on signal


-200 0 200 400 600 800 1000 1200 1400 1600 1800

10000

Inte

nsity

(a.u

.)

Time (ps)

Double switch using two probes at k1 and k2

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Polariton transistor