E. Smalbrugge

Integrated two-state AWG-based multiwavelength laser

An integrated InP-InGaAsP two-state coupled-laser device for use in optical packet switching and signal processing is presented. The two states are identified by distinct lasing wavelengths. Single-mode lasing occurs in both states and the contrast ratio between the two states is 35 dB. Switching between states with optical pulses is demonstrated. The use of an arrayed waveguide grating (AWG) and ring laser configuration permits monolithic integration without the need for cleaved facets. How the AWG can be used to obtain partial isolation between multiple interconnected devices is also discussed.

Coupled Mach–Zehnder interferometer memory element

Two active Mach-Zehnder interferometers are integrated in a monolithic InP/InGaAsP photonic integrated circuit. Together they form a crucial component for optical signal processing: an optical memory element or set-reset flip-flop. The switching time for this initial device is approximately 200 ps. The photonic integrated circuit contains active and passive optical components, including electro-optic phase shifters.

Integrated phased-array 1×16 photonic switch for WDM optical packet switching application

Integrated InP/InGaAsP phased-array 1×16 optical switch is fabricated and characterized for broadband WDM optical packet switching. Wavelength-insensitive operation covering the C-band and penalty-free transmission of 40-Gbps signal are demonstrated.

Retrieving pulse profiles from pump-probe measurements on magnetization dynamics

A method for back-tracing magnetic field pulses in pump-probe-type magnetization dynamics measurements is presented. Solving vectorially the Landau–Lifshitz–Gilbert equation for our field-induced measurement geometry yields field pulse profiles fulfilling the theoretical expectations on a 100 ps timescale. Applying the method to our earlier, all-optical-type pump-probe measurements, the claim that the optical pulse triggers an ultrafast anisotropy field pulse gets a direct proof: we derive a pulse consisting of a delta-peak type, full width at half maximum <5u2009ps impulse on top of a very fast rising step-like profile. Application of the method to other, less trivial pump-probe schemes can contribute to the development of novel type magnetic recording technologies.

Wavelength controlled InAs/InP quantum dots for telecom laser applications

This article reviews the recent progress in the growth and device applications of InAs/InP quantum dots (QDs) for telecom applications. Wavelength tuning of the metalorganic vapor-phase epitaxy grown single layer and stacked InAs QDs embedded in InGaAsP/InP (100) over the [emailxa0protected] region at room temperature (RT) is achieved using ultra-thin GaAs interlayers underneath the QDs. The GaAs interlayers, together with reduced growth temperature and V/III ratio, and extended growth interruption suppress As/P exchange to reduce the QD height in a controlled way. Device quality of the QDs is demonstrated by temperature-dependent photoluminescence (PL) measurements, revealing zero-dimensional carrier confinement and defect-free InAs QDs, and is highlighted by continuous-wave ground-state lasing at RT of narrow ridge-waveguide QD lasers, exhibiting a broad gain spectrum. Unpolarized PL from the cleaved side, important for realization of polarization insensitive semiconductor optical amplifiers, is obtained from closely stacked QDs due to vertical electronic coupling.

All Optical Packet Switching above 80 Gb/s

All-optical packet switching is discussed. In particular, we focus on the utilisation of monolithically integrated building to achieve high-bit-rate operation.

Chaotic quantum-dot InAs/InGaAsP/InP (100) twin-stripe lasers for secure encrypted communication

Quantum-dot twin-stripe lasers have been fabricated and characterized. Dynamic features have been observed indicating regimes of chaotic operation that make these lasers suitable for chaotic-encryption application.

High Bit-Rate All-Optical Packet Switching

All-optical packet switching at high bit-rates is discussed. We focus on the utilizing monolithically integrated devices to achieve high-bit-rate operation

Cross Waveguide Grating Experimental Demonstration

We report the first time ever fabrication and characterisation of a Cross Waveguide Grating (XWG) device.