Ultrafast optical switching in three-dimensional photonic crystals.

TLDR: The first experimental investigation of ultrafast optical switching in a three-dimensional photonic crystal made of a Si-opal composite is presented and results are analyzed within a model based on a two-band mixing formalism.

Abstract: We present the first experimental investigation of ultrafast optical switching in a three-dimensional photonic crystal made of a Si-opal composite. Ultrafast (30 fs) changes in reflectivity around the photonic stop band up to 1% were measured for moderate pump power $(70\text{ }\text{ }\ensuremath{\mu}\mathrm{J}/{\mathrm{c}\mathrm{m}}^{2})$. Short-lived photoexcited carriers in silicon induce changes in the dielectric constant of Si and diminish the constructive interference inside the photonic crystal. The results are analyzed within a model based on a two-band mixing formalism.

Full text

ULTRAFAST OPTICAL SWITCHING
IN THREE-DIMENSIONAL
PHOTONIC CRYSTALS
Ultrasnel optisch schakelen
in driedimensionale fotonische kristallen

ULTRAFAST OPTICAL SWITCHING
IN THREE - DIMENSIONAL
PHOTONIC CRYSTALS
Ultrasnel optisch schakelen
in driedimensionale fotonische kristallen
(met een samenvatting in het Nederlands)
PROEFSCHRIFT
TER VERKRIJGING VAN DE GRAAD VAN DOCTOR AAN
DE UNIVERSITEIT UTRECHT OP GEZAG VAN DE RECTOR
MAGNIFICUS, PROF. DR. W. H. GISPEN, INGEVOLGE
HET BESLUIT VAN HET COLLEGE VOOR PROMOTIES
IN HET OPENBAAR TE VERDEDIGEN OP MAANDAG
6 SEPTEMBER 2004 DES MIDDAGS TE 14.30 UUR
DOOR
Dmitry Anatolievich Mazurenko
geboren op 26 Januari 1974 te Leningrad, USSR

PROMOTOR: PROF. DR. J. I. DIJKHUIS
FACULTEIT DER NATUUR- EN STERRENKUNDE
UNIVERSITEIT UTRECHT

CIP-DATA KONINKLIJKE BIBLIOTHEEK, DEN HAAG
Mazurenko, Dmitry Anatolievich
ULTRAFAST OPTICAL SWITCHING
IN THREE-DIMENSIONAL PHOTONIC CRYSTALS
Dmitry Anatolievich Mazurenko − Utrecht: Universiteit Utrecht,
Faculteit der Natuur- en Sterrenkunde
Thesis Universiteit Utrecht − with a summary in Dutch
ISBN 090-393-3772-1

Frequently asked questions

Q1. What have the authors contributed in "Ultrafast optical switching in three-dimensional photonic crystals ultrasnel optisch schakelen in driedimensionale fotonische kristallen ultrafast optical switching in three - dimensional photonic crystals ultrasnel optisch schakelen in driedimensionale fotonische kristallen" ?

The authors describe two pump-probe setups designed for studying the dynamical ultrafast optical properties of photonic crystals down to the femtosecond time domain. 

Q2. How did the free carriers in silicon photonic crystals react with the electronic bandgap?

In silicon photonic crystals free carriers were excited via infrared two-photon absorption, while in AlGaAs photonic crystals, carriers were excited by weak absorption at the edge of the electronic bandgap of AlGaAs. 

Q3. Why does the Bragg light emerge as a cone?

Due to structural defects in the opal lattice [4–7], the Bragg light emerges as a cone extending over several degrees, depending on the point selected on the sample surface. 

Q4. What is the effect of emitted phonons on the silicon reflectivity?

The emitted phonons, namely, lead to an increase of the lattice temperature that affect the refractive index of silicon over pico- and nanoseconds time scales [26]. 

Q5. At what wavelength does the amplitude of the second order PSB peak return to the initial?

In addition, at ∆t=0.3 ps the authors observe a small blue-shift of the second order PSB peak, which also returns to the initial position for ∆t = 2 ps. 

Q6. What is the effect of the optical pulses on the optical tuning of PSBs?

In their approach, the tuning of PSBs is triggered by femtosecond optical pulses that rapidly modify the mean dielectric constant of the photonic crystal. 

Q7. What frequency is the modulation frequency of the linearly reflected probe and the scattered pump light?

in order to reject the frequency components of the linearly reflected probe and the scattered pump light and to admit exclusively the non-linear signal, the modulation frequencies must be chosen such that ν1l , ν2m for any integers l and m. 

Q8. How to compose a temporal dependence of the dynamic effects?

In order to be able to compose a temporal dependence of the dynamic effects, one needs to perform a set of measurements at different settings of time delay. 

Q9. What is the effect of standing-wave acoustic vibrations on the gold shell?

The authors discovered that the reflectivity is strongly affected by standing-wave acoustic vibrations in the form of coherent expansions and contractions of the gold shell. 

Q10. What is the interesting property of the plane-parallel lenses?

Pendry [24] revealed another fascinating property of these lenses, namely plane-parallel lenses with a negative refractive index that surpass the limit of conventional lenses and are capable to form an image with subwavelength resolution. 

Q11. What is the key to all-optical switching in photonic crystals?

To achieve all-optical switching in photonic crystals, precise knowledge and control of the ultrafast non-linear properties is a prerequisite. 

Q12. What is the effect of the optical excitation on the photonic crystal?

As a result, reflectivity and transmission of the photonic crystal change with a speed and to a degree depending on the duration and power of an optical excitation and the materials that form the photonic crystal. 

Q13. How fast can a three-dimensional photonic crystal be switched?

The authors demonstrate that already at the present level of technology, the switching in a three-dimensional photonic crystals can be made as fast as several tens of femtoseconds with the efficiency of 50% and higher. 

Q14. What is the recent proposal for a quantum efficiency of bulb lamps?

The authors finally mention that photonic structures made of tungsten were recently proposed for enhancing a quantum efficiency of bulb lamps [31, 32]. 

Q15. Why was the spectral region not accessible for measurement?

As noted above, the spectral region from 790 nm to 810 nm was not accessible for measurement due to the strong scattering of 800-nm pump light. 

Q16. How many methods are there to fabricate 3D photonic crystals?

There exist a large number of methods to fabricate 3D photonic crystals with a lattice parameter of the order of a wavelength of visible light.