J. Hanberg

Low-jitter and high-power 40-GHz all-active mode-locked lasers

A novel design strategy for the epitaxial structure of monolithic mode-locked semiconductor lasers is presented. Using an all-active design, we fabricate 40-GHz lasers generating 2.8-ps almost chirp-free pulses with record low high-frequency jitter and more than 7-mW fiber coupled output power.

7x 40 Gb/s base-rate RZ all-optical broadcasting utilizing an electroabsorption modulator.

We experimentally demonstrate all-optical broadcasting through simultaneous 7 x 40 Gb/s base-rate wavelength conversion in RZ format based on cross absorption modulation in an electroabsorption modulator. In this experiment the original intensity-modulated information is successfully duplicated onto seven wavelengths that comply with the ITU-T proposal. The advantages of the proposed wavelength conversion scheme are also discussed.

Optical label encoding using electroabsorption modulators and investigation of chirp properties

A novel scheme of optical label encoding by wavelength conversion based on electroabsorption modulators (EAMs) is reported. Based on the experimental observations, the chirp properties of the wavelength-converted signal are discussed and a wide dynamic range of the chirp /spl alpha/-parameter is found allowed. Compared with cross-gain modulation (XGM) in a semiconductor optical amplifier (SOA), the EAM has several advantages, which make it attractive for optical label encoding or other applications as a wavelength converter.

All-optical demultiplexing and wavelength conversion in an electroabsorption modulator

Cross-absorption modulation in an all electroabsorption modulator is utilised to perform 80/10 Gb/s all-optical demultiplexing. An improvement in receiver sensitivity at 10 Gb/s is demonstrated when wavelength converting.

8×40 Gb/s RZ all-optical broadcasting utilizing an electroabsorption modulator

We experimentally demonstrate all-optical broadcasting through simultaneous 8×40 Gb/s wavelength conversion using an electroabsorption modulator. The original intensity-modulated information is successfully duplicated onto eight wavelengths. The advantages of the proposed wavelength conversion scheme are discussed.

Investigation of reactive‐ion‐etch‐induced damage of InP/InGaAs multiple quantum wells by photoluminescence

The effects of CH&I, reactive ion etching (RIE) on the optical properties of an InP/InGaAs multiple-quantum-well structure have been investigated by low-temperature photoluminescence (PL). The structure consisted of eight InGaAs quantum wells, lattice matched to InP, with nominal thicknesses of 0.5, 1,2,3,5, 10,20, and 70 monolayers, respectively, on top of a 200~nm-thick layer of InGaAs for calibration. The design of this structure allowed etch-induced damage depth to be obtained from the PL spectra due to the different confinement energies of the quantum wells. The samples showed no significant decrease of luminescence intensity after RIE. However, the observed shift and broadening of the PL peaks from the quantum wells indicate that intermixing of well and barrier material increased with etch time. 0 1995 American Institute of Physics.

Experimental characterisation of wavelength conversion at 40Gb/s based on electroabsorption modulators

The optimum operation point for high-speed wavelength conversion in electroabsorption modulators is investigated with respect to conversion efficiency and wavelength chirp. In particular, pump power, reverse bias and probe wavelength are found to be important operation parameters.

Design and evaluation of mode-locked semiconductor lasers for low noise and high stability (Invited Paper)

We present work on design of monolithic mode-locked semiconductor lasers with focus on the gain medium. The use of highly inverted quantum wells in a low-loss waveguide enables both low quantum noise, low-chirped pulses and a large stability region. Broadband noise measurements are performed and used to confirm the design principles.

2.5 Gbit/s modulation of 1300 nm single-mode photonic crystal VCSELs

Long wavelength single fundamental mode photonic crystal VCSELs have been fabricated and demonstrated to deliver 1 mW of output power up to 90degC. 2.5 Gbit/s modulation experiments show clear and open eyes

Novel design of low-jitter 10 GHz all-active monolithic mode-locked lasers

Using a novel design, we have fabricated 10 GHz all-active monolithic mode-locked semiconductor lasers that generate 1.4 ps pulses with record-low timing jitter. The dynamical properties of lasers with 1 and 2 QWs are compared.