Dual-polarization VCSEL-based optical frequency comb generation

Poster of: 2015 European Conference on Lasers and Electro-Optics/European Quantum Electronics Conference (CLEO/EUROPE-EQEC 2015)Optical Frequency Comb Generators (OFCG) based on Cost of the Shelf (COTS) laser diodes (LDs) are interesting systems for many applications as they offer compactness and cost efficiency. However, the optical frequency span and the coherence of the modes is still a limiting factor when comparing to combs based on other laser technologies. Among LDs, Vertical-Cavity Surface-Emitting Lasers (VCSELs) under Gain Switching (GS) regime [1] produce record combs in terms of energy efficiency and mode coherence. GS is a well-known nonlinear technique to directly generate OFCGs from LDs

VCSEL-Based Optical Frequency Combs: Toward Efficient Single-Device Comb Generation

Optical frequency combs generators (OFCGs) have demonstrated to be extremely useful tools in a wide variety of applications. The current research trends look toward compact devices that are able to offer high phase correlation between optical lines, and in this sense, mode-locked laser diodes (MLLDs), with repetition frequencies in the few gigahertz (GHz) range, and especially microresonators, with repetition frequencies of hundreds of GHz, are the most promising devices fulfilling these requirements. Nevertheless, focusing in the few GHz frequency rate, MLLDs cannot provide continuous tunability and require special devices that are still far from offering reliability and repeatability for commercial use. In this letter, we demonstrate for the first time the generation of a flat OFCG based on a single commercial vertical cavity surface emitting laser under gain-switching regime with 20 optical lines (spaced by 4.2 GHz) in a 3-dB bandwidth, offering wide tunability range and very high phase correlation between optical modes. This OFCG does not need any external modulator and it is the most energy-efficient OFCG reported to date.Publicad

Continuous wave sub-THz photonic generation with VCSEL-based optical frequency comb

A simple and energy-efficient photonic system to generate continuously tunable, low phase noise, sub-THz waves based on COTS components is presented. The optical scheme is based on the use of a commercial vertical cavity surface emitting laser under gain switching modulation that provides a very flat optical frequency comb generator (OFCG) with 23 modes in a 20 dB bandwidth. The laser only needs 15 dBm continuous wave radiofrequency input power and 9 mA of bias current to provide this OFCG. Two optical injection locking stages filter and amplify the two desired modes that are detected in a photodiode to produce the desired sub-THz signal at the frequency difference of these two selected modes. As an example, demonstrated is the generation of a very stable 88.2 GHz tone with lower linewidth than 10 Hz using a reference of 4.2 GHz to generate the OFCG.The work by Á.R. Criado has been supported by the Spanish Ministry of Science and Technology under the FPI Program, grant no. BES2010-030290Publicad

Quad 14Gbps L-Band VCSEL-based System for WDM Migration of 4-lanes 56 Gbps Optical Data Links

We report on migrating multiple-lane link into an L-band VCSEL-based WDM system. Experimental validation achieves successful transmission over 10 km of SMF at 4x14Gbps. Inter-channel crosstalk penalty is observed to be less than 0.5 dB and a transmission penalty around 1 dB. The power budget margin ranges within 6 dB and 7 dB

All-VCSEL based digital coherent detection link for multi Gbit/s WDM passive optical networks

We report on experimental demonstration of a digital coherent detection link fully based on vertical cavity surface emitting lasers (VCSELs) for the transmitter as well as for the local oscillator light source at the receiver side. We demonstrate operation at 5 Gbps at a 1550 nm wavelength with record receiver sensitivity of -36 dBm after transmission over 40 km standard single mode fiber. Digital signal processing compensates for frequency offset between the transmitter and the local oscillator VCSELs, and for chromatic dispersion. This system allows for uncooled VCSEL operation and fully passive fiber transmission with no use of optical amplification or optical dispersion compensation. The proposed system demonstrates the potential of multi-gigabit coherent passive optical networks with extended reach and increased capacity. Moreover, this is, to the best of our knowledge, the first demonstration of coherent optical transmission systems using a low-cost VCSEL as the local oscillator as well as for the transmitter

Flip-chip integration of tilted VCSELs onto a silicon photonic integrated circuit

In this article we describe a cost-effective approach for hybrid laser integration, in which vertical cavity surface emitting lasers (VCSELs) are passively-aligned and flip-chip bonded to a Si photonic integrated circuit (PIC), with a tilt-angle optimized for optical-insertion into standard grating-couplers. A tilt-angle of 10 degrees is achieved by controlling the reflow of the solder ball deposition used for the electrical-contacting and mechanical-bonding of the VCSEL to the PIC. After flip-chip integration, the VCSEL-to-PIC insertion loss is -11.8 dB, indicating an excess coupling penalty of -5.9 dB, compared to Fibre-to-PIC coupling. Finite difference time domain simulations indicate that the penalty arises from the relatively poor match between the VCSEL mode and the grating-coupler. (C) 2016 Optical Society of Americ

Free-running L-band VCSEL for 1.25 Gbps hybrid radio-fiber cloud optical interconnects

International audienceWe demonstrate a free-running directly-modulated 1580 nm VCSEL suitable for hybrid wireless/optical interconnects supporting cloud data centers. Error-free transmission at 1.25 Gbps was achieved after 6.5 GHz wireless link and 1 km bend-insensitive fiber