IMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL

Optical cavity with high quality factor Q

Photonic crystals course final presentation

Karin Söderström

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 2

Outline

1) Optical cavities and their use (history)

2) Quality factor Q

3) Lots of cavities

4) Applications of Cavities with PHC• Quantum optic

• Frequency selective devices

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 3

• The simplest optical cavity: A Fabry-Pérot resonator is composed of two parallel mirrors

• Associated with an active medium this cavity realized with one mirror with R<100% leads to one of the greatest discovery of the century

Optical cavities and their use

Laser by Th. Maiman Nature 187, 493-494 (1960)

Macro-cavity

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 4

Optical cavities and their use

• One of the first study on resonator lead to the theoretical great result:– By placing a two-level system in a resonator you can modify

(enhance or stop) the spontaneous emission of the two–level system

E.M.Purcell Phys. Rev. 69 (1946) p. 681

• This information lead to many hope in different field:– One photon source

– Quantum entanglement of radiation and matter is possibleThompson, R. J., Rempe, G. & Kimble, H. J. Phys. Rev. Lett. 68, 1132–1135 (1992).

P. Michler, A. Kiraz, C. Becher, W. V. Schoenfeld, P. M. Petroff, Lidong Zhang, E. Hu, and A. Imamoglu (2000) Science 290 (5500), 2282.

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 5

Quality factor Q

Definition: Q=Pin the cavity /PLosses α lifetime photon in the cavity

Q α 1/where is the linewidth

If R , Q . The quality of the information .

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 6

Lots of different cavities

Fabry-Pérot cavity made of two Bragg mirrors

Cavity made by a defect in a photonic crystal

Kerry J. Vahala, Nature, 424, 6950, 839, (2003)

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 7

Outline

1) Optical cavities and their use (history)

2) Quality factor Q

3) Lots of cavities

4) Cavities with PHC• Quantum optic

• Frequency selective devices

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 8

PHC Cavities Applications

• Quantum optics:• Control of the radiative lifetime (Purcell Effect) Fp α

Qmode/Vmode

Painter,O. et al. Science 284, 1819–1821 (1999).

Applications:Data transport in optical fiber.Easy writing and reading of CD, DVD (small spot size)

Miniature laser, LED, VCSEL, W threshold Control of the in a micropillar

Solomon et al,Phys.Rev.lett., 86, 17, 3903, (2001).

t=1.3ns t=280ps

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 9

PHC Cavities Applications

• Quantum optics:– Strong coupling (of great interest due to the mode volume)

single-atom cavity quantum electrodynamics in the strong coupling regime

Theoretically proven: Vuckovic et al, Phys. Rev. E, 65, 016608, (2001)

Experimentally shown: Yoshie et al, Nature 432, 200-203 (2004) for a QD

Applications:Study of center of mass motion: Rempe, Applied physics. B, 60, 233 (1995)Single photon source: B Deveaud-Pledran, et al - US Patent App. 11/394,518, (2006)Beauty of physics BEC Theoretical: E Ostrovskaya, Y Kivshar, Optics Exp. vol12, (2004)

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 10

PHC Cavities Applications

• Frequency devices (the mode volume is less important)

Akahane et al, Nature, 425, 6961, 944, (2003)

Applications:Very small spectrometer, Multiplexer, Demultiplexer, Filters, Spectroscopy

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 11

• Frequency devices (Vmode is less important, here Q=400)

PHC Cavities Applications

Applications: Very small spectrometer, Multiplexer, Demultiplexer

Noda et al, Nature, 407, 608, (2000)

Shinya et al, Optics Exp,14, 25, 12394, (2006)

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 12

PHC Cavities Applications

• Frequency devices (the mode volume is less important)

Applications: Filters

Kuramochi et al, Appl. Phys. Lett., 88, 041112, (2006)

Qth: 7*10^7

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PHC Cavities Applications

• Frequency devices (the mode volume is less important)

Application: Spectroscopy toolA photonic crystal sensor with a resolutionof better than n =0.002 with a Q factor of 400

Chow et al, Optics letters, 29, 10, 1093, (2004)

In this case it is not a bridge: small amount of sample only needed

The CaltechNanofabrication

Group

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• The cavity is the basis to construct devices with photonic crystals with different functionality modes

– Single photon source needed for quantum computation

Conclusions

• Lots of progresses can be made on Q (from theoretical studies) but the limits of the fabrication process can be reached before

• Lots of different applications in many fields– Laser, spectrometer, multiplexer, filter, spectroscopy

Karin SöderströmIMT INSTITUT DE MICROTECHNIQUE NEUCHÂTEL 15

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Thanks for your attention