Simulations of a sub-kilohertz linewidth laser in monolithic indium phosphide

Narrow-linewidth lasers play a crucial role in various applications, including sensing, coherent communication, and quantum communication. Semiconductor lasers achieving narrow linewidths employ long external cavities to extend photon lifetime within the resonator. For monolithically integrated (active-passive) platforms the loss of the passive waveguides puts a limit on this approach, however. To our knowledge, the state-of-the-art linewidth for such monolithic lasers stands at 10 kHz

Evaluation of Attenuation Methods for an Integrated, Weak Coherent Source for Quantum Key Distribution

Quantum key distribution (QKD) systems that use weak coherent states often rely on attenuated lasers to generate signals with an average of less than one photon per pulse. Two ways of attenuating laser light in a weak, coherent, integrated QKD transmitter chip are compared in terms of noise, namely attenuation with Mach-Zehnder (MZ) interferometers and attenuation with semiconductor optical amplifiers (SOAs) biased as attenuators. Results from simulations and experiments on the optical spectrum of the output of the transmitter chip show that under reverse bias conditions the SOAs result in similar noise levels as the MZs. The footprint of the SOAs on the chip, however, is more than 50 times smaller than that of the MZs. This makes them the better candidate for the integrated, weak coherent QKD source

Optical Frequency Comb Generator based on a Monolithically Integrated Ring Laser

Abstract of: European Semiconductor Laser Workshop. Madrid, Spain, September 24-25th 2015.We report the demonstration of an optical-frequency comb generator based on a monolithically integrated ring laser. We have designed a device fabricated in a Multi-Project Wafer (MPW) run in an active/passive integration process from a generic building blocks. Chip fabrication has been carried out on the JePPIX technology platform, within the InP technology MPW run. A passive modelocked ring laser architecture is chosen, due to its ease of integration with other components to achieve photonic integrated circuits (PICs). The -10 dB span of the optical comb obtained is 8.75 nm (1.09 THz) with lines spaced by 10.1 GHz.This work was supported by Spanish Ministerio de Economía y Competitividad DiDACTIC project (TEC2013-47753-C3-3-R) and Consejería de Educación, Juventud y Deporte of Comunidad de Madrid DIFRAGEOS project (P2013/ICE-3004)Publicad

AWG-DBR-based WDM transmitter fabricated in an InP generic foundry platform

We report a novel narrow-linewidth WDM transmitter operating at 10 Gbps per transmission channel with 275 kHz optical linewidth. The device, which integrates an AWG-based laser using selective DBR-mirrors with a Mach-Zehnder modulator array, has been fabricated in a multi-project wafer run in a generic InP-based foundry process.</p

Photonic flip-chip assembly of InP on TriPleX with laser soldering

We present a photonic flip-chip assembly for a 4 mm × 4.6 mm InP die with 58 electrical connections on a 16 mm × 8 mm TriPleX die by using laser soldering. Two laser soldering schemes are investigated and show reliable contacts with a 6 N shear force: (1) using a laser wavelength where silicon is highly transmissive (through-silicon laser soldering) and (2) using a laser wavelength where silicon is not transmissive (heat-conduction laser soldering)