den Jh Jan Hendrik Besten

A compact digitally tunable seven-channel ring laser

A seven-channel ring laser was realized by monolithic integration of a compact 4/spl times/4 PHASAR (de)multiplexer with four amplifiers in InP. The PHASAR was fabricated using a double-etch technique, enabling a total size of the ring laser of only 1/spl times/1.5 mm/sup 2/. Light was coupled out via the outer array waveguides. Reflections are minimized by using mode filters and angled facets. Threshold-currents of 70 mA and a sidemode suppression ratio of 40 dB were measured. In principle, a ring laser with N amplifiers can produce 3N-3 different wavelengths.

Realization and modeling of a 27-GHz integrated passively mode-locked ring laser

We present a realization and the modeling of a 27-GHz integrated extended cavity ring laser that is passively mode-locked. The mode-locked ring laser is fabricated with active-passive integration. Experimental results show that internal reflections are the major factor affecting operation stability. Continuous-wave, self-pulsating, and in small windows of operation mode-locked regimes have been observed. Similar regimes have been observed in our bidirectional laser model. This model describes the semiconductor amplifier and the saturable absorber using rate equations. Our experimental and theoretical results are compared and discussed.

An integrated 4 x 4-channel multiwavelength laser on InP

We present a compact 16-channel digitally tunable laser integrated on InP with the possibility to produce groups of four wavelengths at the same time. The cavity contains two arrays of four semiconductor optical amplifiers (SOAs) with two periodical four-channel intracavity phased arrays (PHASARs) with channel spacings of 100 and 400 GHz. By activating two out of the eight SOAs, 16 different wavelengths can be selected. Light was coupled out of the cavity by waveguides placed in the second focal order of the PHASARs. Reflections from the end facets of the wafer are minimized using mode filters and angled output waveguides.

Wavelength selection in an integrated multiwavelength ring laser

The wavelength selection mechanism of a compact integrated multiwavelength ring laser is demonstrated. The device contains four semiconductor optical amplifiers, a compact arrayed waveguide grating and passive waveguides integrated on a single InP wafer. The device can produce seven different wavelengths through biasing one or two out of the four amplifiers. Comparison of calculated and measured subthreshold laser spectra demonstrates the role of crosstalk in the arrayed waveguide grating in the laser and allows the crosstalk to be quantified. A rate-equation model of the laser and measurements are presented that describe the switching between wavelengths of the laser as a function of bias currents. A comparison between the measured data and the model is made.

Modelling and design of a travelling-wave electro-optic modulator on InP

Based on a rigorous vectorial analysis, a fast travelling-wave Mach–Zehnder modulator is modelled and designed. The cross-section of the semiconductor layer stack and the lossy electrodes are carefully modelled using the method of lines in order to investigate propagation characteristics, velocity and losses. This yields an accurate microwave and optical field distribution to explain the behaviour of the component. In order to enhance the modulation efficiency, design curves are derived and the cross-sectional dimensions for minimum microwave loss are determined. The loss of the optimized modulator agrees very well with small-signal measurements up to 40 GHz and HFSS simulations. The layerstack of the fabricated device is suitable for integration with InP multi-wavelength lasers.

Integrated passively modelocked InGaAsP ringlasers with active-passive integration

Integrated modelocked ring lasers with fundamental repetition rates of 35 and 26Ghz were fabricated in InGaAsP using active-passive integration. First measurements shows pulses down to 1.2ps width can be produced.

Multiwavelength lasers using AWGs

Multiwavelength lasers using AWGs can be used as digitally tunable lasers with simple channel selection, and for generating multiple wavelengths simultanously. In this paper a number of different configurations is reviewed.Multiwavelength lasers using AWGs can be used as digitally tunable lasers with simple channel selection, and for generating multiple wavelengths simultanously. In this paper a number of different configurations is reviewed.

Corrections to "An integrated coupled-cavity 16-wavelength digitally tunable laser"

We present a digitally tunable laser that was realized by coupling two wavelength periodical four-channel lasers. The lasers were coupled with a multimode interference coupler, in such a way that the device has a common intracavity output waveguide containing the full multiplexed signal. In the two laser cavities, 1 /spl times/ 4 PHASARs were used with a channel spacing of 100 and 400 GHz, respectively. By coupling each PHASAR to four semiconductor optical amplifiers, 4 /spl times/ 4 channels were generated. The measured SMSR for each of the 16 wavelengths is better than 40 dB.