2 Image MEB d’un ruban laser après fabrication. . . vii 7 Profils d’intensité et de phase des impulsions pour des courants d’injection
(de gauche à droite) de 100, 200, 300 et 400 mA. Pour chaque mesure, les valeurs de durée d’impulsion ⌧, d’erreur de reconstruction FROG ", de longueur d’onde centrale c, de largeur du spectre optique à mi-
hauteur F W HM, de dispersion de retard de groupe (GDD – group
delay dispersion) de l’impulsion, de la fibre et totale GDDp, GDDSM F 28
et GDDtot et de durée d’impulsion minimale qui peuvent être obtenues
sont indiquées. . . xii 8 Montage expérimental pour la technique de réflectométrie optique dans
le domaine fréquentiel. . . xiii 9 Exemples de mesure de dispersion pour des valeurs différentes de disper-
sion de retard de groupe programmées sur le filtre optique. . . xiv 11 Montage expérimental pour les mesures de transmission WDM en util-
isant le format de modulation OFDM à bande latérale unique et à détection directe. . . xvi 13 (a) Spectre optique filtré du laser à blocage de modes à bâtonnets
quantiques avec ISL de 44.7 GHz, (b) taux d’erreur binaire pour les différentes porteuses optiques en utilisant les signaux OFDM à 28.2 Gb/s (carrés noirs) et 33.6 Gb/s (cercles rouges), respectivement pour des transmissions à travers 3 et 50 km de fibre SMF-28, (c) bruit relatif d’intensité moyen mesuré dans la bande 0-10 GHz pour tous les modes, et (d) diagramme de constellation 16-QAM pour le mode central, après une transmission à travers 3 km de fibre SMF-28. (e)-(h) Les mêmes quantités que dans (a)-(d), mais pour le laser à blocage de modes à
bâtonnets quantiques avec ISL de 22.7 GHz. . . xviii 1.1 Optical frequency comb with f–2f interferometer for carrier offset fre-
1.2 Qualitative summary of optical frequency comb technologies as function of fractional bandwidth / and frequency spacing fr(adapted from [25]). 10
1.3 Functional behavior of |A(t0)|2/E2
0 for N = 5, 7 and 9. . . 14
1.4 Functional behavior of |A(t0)|2/E2
0 for N = 9 and ✓ = 0, 0.05, 0.1 and 0.15. 15
1.5 Functional behavior of |A(t0)|2/E2
0 for N = 61 and m = 1, 2, 3 and 4. . 16
1.6 Second harmonic generation second harmonic generation (SHG) auto- correlation autocorrelation (AC) optical setup. . . 21 1.7 Optical heterodyning setup. . . 23 1.8 Delayed self heterodyne (DSH) technique setup. . . 23 1.9 Biasing condition for active and hybrid mode-locking. . . 30 2.1 Density of states for bulk material, quantum well, quantum wires and
quantum dots. . . 37 2.4 Sketch of a broad area laser for material characterization. . . 44 2.6 Alcor simulation of ridge waveguide laser for single transverse mode
operation. . . 47 2.8 inductively coupled plasma reactive ion etching (ICP-RIE) interferogram
of an etching test on a quantum dash (QDash) structure. Phase shifts in the interferogram indicate material transitions. Ridge etching should be interrupted around the etch-stop + top layers in order to ensure single transverse mode operation of the lasers. . . 48 2.10 scanning electron microscopy (SEM) picture of a processed laser structure. 50 2.12 SEM picture of a 6 dash-in-a-barrier (DBAR) buried ridge stripe (BRS)
laser (courtesy of F. Lelarge, III-V Lab). . . 52 3.7 Light-current characteristic for the 1.4-mm-long, single-section InAs/GaAs
quantum dot (QD) laser. . . 59 3.11 Reconstructed pulse intensity and phase for injection currents (from
left to right) of 100, 200, 300 and 400 mA. The values of pulse width ⌧, frequency-resolved optical gating (FROG) reconstruction error ", central wavelength c, spectral full width at half maximum (FWHM) F W HM, pulse, fiber-induced and total group delay dispersion GDDp,
GDDSM F 28 and GDDtot and minimum pulse width achievable ⌧min,
are reported for each measurement. . . 65 3.12 single sideband phase noise (SSBPN) curves recorded every ⇡ 30 s for a
3.15 Compound reflectivity modulation A(R) as function of laser facet re- flectivity R for different values of effective reflectivity Re of coupling
optic. . . 71 3.17 Micrograph picture of the distributed Bragg reflector (DBR) laser inte-
grated with a tapered semiconductor optical amplifier (SOA) (Courtesy of S. Joshi, III-V Lab). . . 73 4.2 Schematic of the 4-f Pulse Shaper concept. . . 82 4.3 Measured transfer function of a 1 THz bandwidth bandpass filter gener-
ated with the Waveshaper (blue), in comparison with the programmed filter shape (red). . . 82 4.4 Examples of group delay dispersion measurements for different values of
group delay dispersion (GDD). . . 83 4.6 Reflectograms simulated in the case of constant increase of the optical
path length difference with a speed of w = 0.1 m/s for tunable laser source (TLS) sweep rates of 5,10, and 15 nm/s. . . 86 4.8 Reflectograms measured for the QDash based SOA as function of injec-
tion current. Peaks corresponding to fiber splicing, lensed fiber tip and SOA output facet are indicated by arrows. In the inset: magnification of the reflectogram curve for I = 150 mA around the peaks corresponding to lensed fiber tip. A second peak representative of the SOA input facet is readily identifiable. . . 90 5.2 Example of mapping between groups of bits and numbers in the complex
plane for 16-quadrature amplitude modulation (QAM) modulation for- mat. Gray code is used in the 16-QAM constellation to facilitate error correction at the receiver. . . 94 5.3 Role of orthogonal frequency division multiplexing (OFDM) cyclic prefix
at the receiver side. The relative delay ⌧ between different subcarriers within the same OFDM symbol Si causes inter-symbol interference
(ISI) in the absence of cyclic prefix, while it is compensated with the introduction of such a guard interval. . . 95 5.5 System architectures for all-optical OFDM. . . 98 5.6 Schematic of the experimental setup for direct detection single sideband
5.10 (a) Optical spectrum, (b) RF spectrum, and (c) relative intensity noise (RIN) for selected filtered modes and all modes for the 44.7 GHz QDash laser. (d-f) Same quantities as in (a-c), but for the QDash mode-locked laser (MLL) with 22.7 GHz free spectral range. . . 105 5.11 (a) Filtered optical spectrum of the QDash MLL with 44.7 GHz channel
spacing, (b) measured bit error rate (BER) of the 28.2 Gb/s (black squares) and 33.6 Gb/s (red circles) SSB OFDM data for each channel number, over 3 and 50 km of single mode fiber (SMF), (c) measured average RIN (0-10 GHz) for all modes, and (d) measured constellation diagrams for the central channel after 3 km of SMF. (e-h) Same results as in (a-d), but for the QDash MLL with 22.7 GHz channel spacing. . . 105