Vertically-Coupled Microring Laser Array for Dual-Wavelength Generation

We report the first demonstration of continuous-wave operation of a tunable, compact microring laser array based on a vertical-coupling architecture, well suited to larger-scale integration. Wavelength separation tunability from 4.9 to 6.3nm is observed

Wafer-Bonded Active/Passive Vertically Coupled Microring Lasers

We summarize the results of a European Project entitled WAPITI (Waferbonding and Active Passive Integration Technology and Implementation) dealing with the fabrication and investigation of active/passive vertically coupled ring resonators, wafer bonded on GaAs, and based on full wafer technology. The concept allows for the integration of an active ring laser vertically coupled to a transparent bus waveguide. All necessary layers are grown in a single epitaxial run so that the critical coupling gap can be precisely controlled with the high degree of accuracy of epitaxial growth. One key challenge of the project was to establish a reliable wafer bonding technique using BCB as an intermediate layer. In intensive tests we investigated and quantified the effect of unavoidable shrinkage of the BCB on the overall device performance. Results on cw-operation, low threshold currents of about 8 mA, high side-mode suppression ratios in the range of 40 dB and large signal modulation bandwidths of up to 5 GHz for a radius of 40 μm shows the viability of the integration process

A plane-wave boundary method for analysis of bent optical waveguides

A plane-wave boundary method is proposed for the analysis of bent optical waveguides. The realization of the method is based on the equivalent straight waveguide approach and consists of two steps. At first, the plane-wave boundary condition is introduced at the computational boundary where the outgoing wave is expected. Then, the optimum location of the computational boundary is determined, corresponding to the maximum of radiation power loss. The optimized computational window helps to significantly reduce the influence of the nonphysical reflections of the outgoing wave caused by the particular index profile of bent waveguide structures in the straight waveguide approach. Using this method, the propagation constants and radiation losses are determined for waveguides with different bend radii. In contrast to methods based on the absorption concept, the proposed method does not require the introduction of additional parameters

Thermal analysis of bond layer influence on performance of an all-active vertically coupled, microring resonating laser

The vertical coupling of active InP based ring resonators and passive feeding waveguides necessitates the use of a waferbonding technology in the fabrication process. The required bond material (BCB) has a low thermal conductivity and will strongly influence the operating temperature and thus the performance of the ring resonator through its insulating effect. A comprehensive thermal analysis of a proposed vertically coupled ring resonator of 50 µm outer radius is undertaken during the design phase to determine the thermal impact of: the design of the wafer bond, the design of the passivation layer and the optical power levels. Thermal abatement strategies for semiconductor lasers are presented

7Gb/s direct modulation of vertically coupled microring lasers

We report on the properties of directly modulated active-passive integrated microring lasers fabricated using full wafer bonding techniques. Bit rates up to 7Gb/s are reported for the first time, together with a 50km SMF transmission

40 Gbit/s directly modulated passive feedback laser

High speed directly modulated lasers are key devices for compact, low cost transmitters. In this paper we describe the mechanism of modulation bandwidth enhancement by passive feedback sections and the characteristics of accordingly fabricated 1.55 µm InGaAsP/InP lasers. The system performance at 40 Gbit/s is analysed, including VSR transmission and BER measurements, and the potential for chirp tuning is shown

Halbleiterlaser und Verfahren zum Betreiben eines Halbleiterlasers

WO 2009036904 A1 UPAB: 20090409 NOVELTY - The semiconductor laser has an active region (1) which is designed as a distributed feedback laser (DFB) laser, and a passive resonator section (2), which is optically coupled to the active region. The active region has two sections (7,8) with two Bragg gratings, where the latter Bragg grating differs from the former Bragg grating. The two Bragg gratings differ from one another such that one and only one main mode of a DFB mode spectrum of the former section overlaps with one of the two main modes of a DFB mode spectrum of the latter section. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for operating a semiconductor laser. USE - Semiconductor laser. ADVANTAGE - The semiconductor laser has an active region which is designed as a distributed feedback laser, and a passive resonator section, which is optically coupled to the active region, and hence enables very high frequency modulation of laser radiation