Showing papers by "Finisar published in 2016"
TL;DR: In this paper, the authors show that Si photonics is currently significantly more expensive than MM VCSEL for single channel, but that it can make a successful entry into the four channel single mode market with significant growth, capturing 20% of the data center market.
Abstract: Recent technical and commercial milestones in Silicon Photonics technology including its introduction into commercial foundries, and successful integration of most optical components, as well as the choice of single mode fiber in some mega data centers have prompted the speculation that Si photonics is the new low cost solution for optical interconnects and that it may replace multi-mode vertical cavity surface emitting lasers (MM VCSEL). We show that the dominant technology has to offer the lowest cost for the single channel transceiver application, which represents 90% of the data center market and which historically dominates sales. We show that Si photonics is currently significantly more expensive than MM VCSEL for single channel, but that it can make a successful entry into the four channel single mode market with significant growth, capturing 20% of the data center market. We discuss the challenges with Si/InP integration; i.e., hybrid lasers for breaking the cost barrier and to enter the market. We show that both MM VCSEL and Si photonics technologies can operate at 50 Gb/s. We discuss the transmission reach limitations of Si photonics and MM VCSEL and show an example of reach extension for 100 Gb/s using MM VCSEL to 300 m of MM fiber. In addition we show that MM VCSEL has fundamentally lower power consumption than Si photonics and is a good candidate for super-computing applications.
86 citations
20 Mar 2016
TL;DR: A short-cavity distributed reflector (DR) laser achieved a 3-dB BW of 55 GHz when used to demonstrate single-channel 112-Gb/s PAM-4 transmission without pre-emphasis.
Abstract: A short-cavity distributed reflector (DR) laser achieved a 3-dB BW of 55 GHz. The DR laser was used to demonstrate single-channel 112-Gb/s PAM-4 transmission without pre-emphasis.
76 citations
TL;DR: In this paper, a high-speed 1310-nm Al-MQW buried-hetero laser having 29GHz bandwidth was used to compare 28-Gbaud four-level pulse-amplitude-modulation (PAM4) and 56-Gb/s non-return to zero (NRZ) transmission performance.
Abstract: We have developed a high-speed 1310-nm Al-MQW buried-hetero laser having 29-GHz bandwidth (BW). The laser was used to compare 28-Gbaud four-level pulse-amplitude-modulation (PAM4) and 56-Gb/s nonreturn to zero (NRZ) transmission performance. In both cases, it was possible to meet the 10-km link budget, however, 56-Gb/s NRZ operation achieved a 2-dB better sensitivity, attributable to the wide BW of the directly modulated laser and the larger eye amplitude for the NRZ format. On the other hand, the advantages for 28-Gbaud PAM4 were the reduced BW requirement for both the transmitter and the receiver PIN diode, which enabled us to use a lower bias to the laser and a PIN with a higher responsivity, or conversely enable the possibility of high temperature operation with lower power consumption. Both formats showed a negative dispersion penalty compared to back-to-back sensitivity using a negative fiber dispersion of −60 ps/nm, which was expected from the observed chirp characteristics of the laser. The reliability study up to 11 600 h at 85 °C under accelerated conditions showed no decrease in the output power at a constant bias of 60 mA.
41 citations
20 Mar 2016
TL;DR: This work demonstrates 51.5625Gbps PAM4 transmission over ≥ 150 m next generation wide band MMF using SWDM TOSAs from 850 nm to 940 nm indicating an aggregated 206.25 Gb/s speed achievable on a single WBMMF.
Abstract: We demonstrate 51.5625Gbps PAM4 transmission over ≥ 150 m next generation wide band MMF using SWDM TOSAs from 850 nm to 940 nm indicating an aggregated 206.25 Gb/s speed achievable on a single WBMMF.
30 citations
TL;DR: The inner eye optical modulation amplitude (OMA) receiver sensitivities were measured and compared and the measured inner eye OMA was improved to -21.0 dBm for -58 ps/nm of CD at the KP4 BER threshold using an APD.
Abstract: Real-time 52 Gbps PAM4 transmission is demonstrated over single mode fiber (SMF) using a directly modulated laser (DML) and a PHY chip. The inner eye optical modulation amplitude (OMA) receiver sensitivities were measured and compared using avalanche photodetector (APD) and PIN photodetector (PD) for the maximum and minimum chromatic dispersions (CDs) of 400GBase-LR8 link. The measured inner eye OMAs were −17.8 dBm and −18.8 dBm for + 10 ps/nm and −58 ps/nm of CDs at the KP4 bit error rate (BER) threshold of 2 × 10−4 using a PIN PD, respectively. The measured inner eye OMA was improved to −21.0 dBm for −58 ps/nm of CD at the KP4 BER threshold using an APD. Negligible OMA penalty (< 0.4 dB) was captured for operating DML at different bias currents of 40 mA and 60 mA using a PIN PD and an APD for both positive and negative CDs at the KP4 BER threshold.
25 citations
Patent•
19 Dec 2016TL;DR: In this paper, Fan out region optically coupled to the core waveguide in the same layer of the surface coupled edge emitting laser was used to reduce the alignment requirements between the laser chip and the photonic integrated circuit.
Abstract: A system includes a surface coupled edge emitting laser (212) that includes a core waveguide, a fan out region optically coupled to the core waveguide in a same layer of the surface coupled edge emitting laser as the core waveguide; and a first surface grating (206) formed in the fan out region; and a photonic integrated circuit (PIC) that includes an optical waveguide and a second surface grating formed in an upper layer of the PIC, wherein the second surface grating is in optical alignment with the first surface grating. Due to the tapered shape of the fan out grating (206) alignment requirements between the laser chip and the PIC are reduced.
25 citations
22 May 2016
TL;DR: In this article, a 108GS/s track-and-hold amplifier manufactured in a 55nm SiGe BiCMOS technology achieves 40GHz bandwidth with THD and SFDR of −49 dB and 55 dB, respectively, made possible by the use of a new MOS-HBT quasi-CML switch operating in class-AB mode.
Abstract: A 108GS/s track-and-hold amplifier manufactured in a 55nm SiGe BiCMOS technology achieves 40GHz bandwidth with THD and SFDR of −49 dB and 55 dB, respectively. This performance is made possible by the use of a new MOS-HBT quasi-CML switch operating in class-AB mode, which results in an overall power consumption of 87 mW from 2.5V and 1.8V power supplies. The circuit targets time-interleaved ADC front-ends in next generation 64Gbaud fiber-optic receivers.
20 citations
20 Mar 2016
TL;DR: Direct modulation of a 10-nm tunable DBR laser was used to demonstrate 20 km transmission, high fiber-coupled power operation, low power consumption, and frequency stabilization in burst mode operation for the NGPON2 application.
Abstract: Direct modulation of a 10-nm tunable DBR laser was used to demonstrate 20 km transmission, high fiber-coupled power operation (> 10 mW), low power consumption, and frequency stabilization in burst mode operation for the NGPON2 application.
19 citations
TL;DR: It is demonstrated successful transmission of four 45 Gbps PAM4 single-channels through OM4 multimode fibers and wideband MMF using a Pam4 PHY chip and four vertical cavity surface emitting lasers with wavelengths ranging over short wavelength division multiplexing (SWDM) grid.
Abstract: We demonstrate successful transmission of four 45 Gbps PAM4 single-channels through OM4 multimode fibers (MMFs) and wideband MMF using a PAM4 PHY chip and four vertical cavity surface emitting lasers (VCSELs) with wavelengths ranging over short wavelength division multiplexing (SWDM) grid. Real-time bit error ratios (BERs) < 2 × 10−4 were achieved for all four 45 Gbps PAM4 SWDM grid channels over 100 m, 200 m, and 300 m of wideband OM4 MMFs. All four channel received PAM4 optical eyes are shown after propagating through 100 m, 200 m, and 300 m of wideband OM4 as well as 100 m and 200 m conventional OM4 MMFs. The measured BERs as a function of the inner eye optical modulation amplitudes (OMAs) are shown for all four SWDM grid channels. Inner eye OMAs ranged from −16.2 dBm to −13.5 dBm for different channels over different OM4 MMF types at the KP4 BER threshold of 2 × 10−4.
18 citations
20 Mar 2016
TL;DR: Real time BERs<;2e-4 were achieved for four SWDM grid channels in the 850-950nm wavelength range over 100m/200m/300m of wideband OM4 fibres.
Abstract: Successful 180 (4×45) Gbps transmission is demonstrated over OM4 fibres using a 45-Gbps-PAM4 chip. Real time BERs<2e-4 were achieved for four SWDM grid channels in the 850–950nm wavelength range over 100m/200m/300m of wideband OM4 fibres.
18 citations
Patent•
11 Mar 2016TL;DR: A differential TWE MZM includes a differential driver, first and second capacitors, and first-and second terminations as mentioned in this paper, and the differential driver includes a first differential output and a second differential output that collectively form a differential pair.
Abstract: A differential TWE MZM includes a differential driver, first and second capacitors, and first and second terminations. The differential driver includes a first differential output and a second differential output that collectively form a differential pair. The first differential output is DC coupled to a first arm optical phase shifter of a TWE MZM. The second differential output is DC coupled to a second arm optical phase shifter of the TWE MZM. The first capacitor AC couples the second differential output to the first arm optical phase shifter. The second capacitor AC couples the first differential output to the second arm optical phase shifter. The first and second terminations are coupled to, respectively, the first or second arm optical phase shifter.
Patent•
21 Apr 2016
TL;DR: In this article, a method of transmitting data may include converting a stream of serial data bits into a set of parallel quadrature amplitude modulation (QAM) symbols, and then applying a partial discrete Fourier transform-spread technique to transform a block of low-frequency subcarriers into a single-carrier QAM signal.
Abstract: A method of transmitting data may include converting a stream of serial data bits into a set of parallel quadrature amplitude modulation (QAM) symbols. The method may additionally include applying a partial discrete Fourier transform-spread technique to transform a block of low-frequency subcarriers into a single-carrier QAM signal. The single-carrier QAM signal may bear information of a first subset of QAM symbols from the set of parallel QAM symbols. The method may additionally include transforming one or more remaining QAM symbols to form one or more subcarriers. Each of the one or more subcarriers may bear information of a corresponding QAM symbol from the one or more remaining QAM symbols. The method may additionally include generating a hybrid signal that includes the single-carrier QAM signal and the one or more subcarriers. The method may additionally include transmitting the hybrid signal.
26 Jun 2016
TL;DR: In this article, a full-C band tunable laser equipped with an air-gap suspended waveguide structure for efficient thermal heater tuning is described, which can simultaneously meet the requirements for the output power, side-mode suppression ratio, and spectral linewidth for 16-QAM coherent communication system.
Abstract: A full-C band tunable laser equipped with an air-gap suspended waveguide structure for efficient thermal heater tuning is described. It is shown that the monolithic tunable laser can simultaneously meet the requirements for the output power, side-mode suppression ratio, and spectral linewidth for 16-QAM coherent communication system. Together with an optimized design for the Bragg grating and a reduced optical loss for thermally-tuned un-doped waveguide, a high SMSR of 54.5 dB, an output power of 19 dBm, and 80 kHz linewidth over 103 channels across the C-band were achieved. A possibility for further reduction of the heater tuning power is also discussed.
18 Jul 2016
TL;DR: In this article, a 112 Gb/s single-carrier, single-polarization PAM-4 system is demonstrated using a 1310 nm directly modulated laser.
Abstract: A 112 Gb/s single-carrier, single-polarization PAM-4 system is demonstrated using a 1310 nm directly modulated laser. Transmission over 20 km SMF without optical amplification is achieved by channel pre-compensation and laser nonlinear distortion management.
20 Mar 2016
TL;DR: Successful transmission of 52Gb/s PAM4 through -58 and +10 ps/nm of SMF using a single chip and directly modulated laser is presented.
Abstract: We present successful transmission of 52Gb/s PAM4 through −58 and +10 ps/nm of SMF using a single chip and directly modulated laser. The receiver sensitivities are compared using APD and PIN PD at the receiver.
Patent•
1 Aug 2016TL;DR: In this article, a polarization beam splitter (PBS), a polarization controller, and a forward error correction (FEC) decoder are configured to correct a burst of errors resulting from resetting one of the phase shifters based on error correction code (ECC) encoded in the data signal.
Abstract: An example embodiment includes optical receiver that includes a polarization beam splitter (PBS), a polarization controller, and a forward error correction (FEC). The PBS is configured to split a received optical signal having an unknown polarization state into two orthogonal polarizations (x′-polarization and y′-polarization). The polarization controller includes no more than two couplers and no more than two phase shifters per wavelength channel of the x′-polarization and the y′-polarization. The polarization controller is configured to demultiplex the x′-polarization and the y′-polarization into a first demultiplexed signal having an first polarization on which a data signal is modulated and a second demultiplexed signal having a second, orthogonal polarization on which a pilot carrier oscillator signal is encoded. The FEC decoder module is configured to correct a burst of errors resulting from resetting one of the phase shifters based on error correction code (ECC) data encoded in the data signal.
1 Oct 2016
TL;DR: Passband filtering and in-band crosstalk penalties are investigated using WSS filter shapes fitted using a supergaussian model and an analytical model, which is determined to be more accurate than the superGAussian model for stopband fitting and crosStalk penalty assessment.
Abstract: Passband filtering and in-band crosstalk penalties are investigated using WSS filter shapes fitted using a supergaussian model and an analytical model. The analytical model is determined to be more accurate than the supergaussian model for stopband fitting and crosstalk penalty assessment.
1 Sep 2016
TL;DR: The challenges of circuit design for high-speed and high-volume optical interconnect and how SiGe BiCMOS technologies are best suited to address these challenges are discussed andvantages are illustrated.
Abstract: In this paper we will discuss the challenges of circuit design for high-speed and high-volume optical interconnect and how SiGe BiCMOS technologies are best suited to address these challenges. Advantages of SiGe BiCMOS are illustrated through examples of design requirements from optical front-ends (transimpedance amplifier (TIA) and modulator and laser driver) to clock and data recovery (CDR) and serializer and deserializer (SerDes). We will also look ahead to the future and predict product evolution and key requirements of optical interconnects and define the required performance of SiGe BiCMOS technology to address such specifications.
5 Jun 2016
TL;DR: In this paper, the receiver sensitivity of 52 Gbps-PAM4 was investigated over OM3/OM4 fibers in real-time, and the measured sensitivities were compared and correlated with measured fiber bandwidths for 850/880 nm channels.
Abstract: The receiver sensitivity of 52 Gbps-PAM4 is investigated over OM3/OM4 fibers in real time. The measured sensitivities are compared and correlated with measured fiber bandwidths for 850/880 nm channels to examine 104 Gbps SWDM2-PAM4 transmission.
Proceedings Article•
1 Sep 2016TL;DR: In this article, a short cavity distributed reflector (DR) with a modulation bandwidth of 55GHz was developed using the photon-photon resonance and detunedloading effects, and the importance of the chirp parameter for the speed enhancement was discussed.
Abstract: A short cavity distributed reflector (DR) laser with a modulation bandwidth of 55GHz was developed using the photon-photon resonance and detuned-loading effects. The importance of the chirp parameter for the speed enhancement is discussed.
20 Mar 2016
TL;DR: Experimental data is presented demonstrating 100GbE (4×25.8 Gbps) SWDM4 VCSEL technology, andSWDM4 transmission over 200m and 300m of wideband OM4 fibers, and novel modal excitation method, 25 Gbps NRZ transmission over 300m OM3 is shown.
Abstract: Experimental data is presented demonstrating 100GbE (4×25.8 Gbps) SWDM4 VCSEL technology, and SWDM4 transmission over 200m and 300m of wideband OM4 fibers. All NRZ SWDM4 channels achieved error-free transmission at 200m, and BER < 1e-9 at 300m. In addition, successful 180 (4×45) Gbps transmission is demonstrated over 300m wideband OM4 fibers using a 45-Gbps-PAM4 chip. Real time BERs < 2e-4 were achieved for all four SWDM grid channels in the 850–950nm wavelength range. Precise modal excitation in MMF fibers for improving the fiber bandwidth by minimizing modal dispersion is also discussed. Using our novel modal excitation method, 25 Gbps NRZ transmission over 300m OM3 is shown.
Patent•
24 Mar 2016TL;DR: In this paper, a method and apparatus used for automatic bias stabilization of a DP IQM based on MZM for transmitting DP-QPSK optical data and/or DP-16QAM optical data is presented.
Abstract: Embodiments include a method and apparatus used for automatic bias stabilization of a DP IQM based on MZM for transmitting DP-QPSK optical data and/or DP-16QAM optical data. The apparatus simultaneously dithers DC-bias voltages of in-phase child, quadrature-phase child, and parent MZMs with three different dither patterns in time-domain which are mutually orthogonal to each other in the frequency-domain for X and Y polarization IQ modulators. Tap monitor photodiodes detect an interference term between these three dither patterns for each polarization. The interference term is sampled using an ADC in the time domain. The time-synchronous detection method may solve a set of three simultaneous linear partial differential equations with three unknowns to compute controlled DC-bias voltages to set on the respective MZM with a solution set which may iteratively converge to a unique solution, thereby biasing the child MZM in dual-polarization IQM to transmission minimum and parent MZM in quadrature transmission.
Patent•
10 Mar 2016TL;DR: In this paper, a multichannel transmitter optical subassembly that includes a plurality of lasers and a signal combiner is described, where each of the light signals having a wavelength within one of the plurality of wavelength bands.
Abstract: Embodiments described herein include a multichannel transmitter optical subassembly that includes a plurality of lasers and a signal combiner. The plurality of lasers may be configured to emit light each with a different one of a plurality of light signals, each of the plurality of light signals having a wavelength within one of a plurality of wavelength bands. The signal combiner may be disposed relative to the plurality of lasers to receive the plurality of light signals. The signal combiner may include at least one surface having an optical coating that reflects at least one of the light signals of the plurality of light signals and transmits at least one of the light signals of the plurality of light signals.
20 Mar 2016
TL;DR: 400Gb/s single carrier transmission over 80km standard fiber using highly integrated optics in CFP2 form factor is achieved just below soft decision FEC limit while the improvement is reported with discrete receiver.
Abstract: We report 400Gb/s single carrier transmission over 80km standard fiber using highly integrated optics in CFP2 form factor. 400Gb/s is achieved just below soft decision FEC limit while the improvement is reported with discrete receiver.
TL;DR: In this paper, the authors present results from finite element analysis mockups for the stresses, strains, and the frictional flash temperatures that occur when a recording head in a disk drive impacts an asperity bump on the rotating disk surface.
Abstract: Here we present results from finite element analysis mockups for the stresses, strains, and the frictional flash temperatures that occur when a recording head in a disk drive impacts an asperity bump on the rotating disk surface. These simulations also included the very thin carbon protective overcoats that are routinely used to protect the head and disk media surfaces during this impact, allowing us to predict more accurately the wear resistances for these surfaces during these types of impacts. Using these simulations, we are able to perform parametric studies of how the tribological performance of these interfaces is affected by amount of interference, asperity width, material properties, and frictional coefficients. Good agreement is found between these simulation results for flash temperatures from frictional heating and the measured values from a previous experimental study from our laboratory for the temperature rise at the embedded contact sensor within the recording head.
Patent•
30 Mar 2016TL;DR: In this paper, a host-equalized optical transceiver includes a driver analog interface, a linear laser diode driver (LLDD), and an optical transmitter, which is configured to receive the driving signal from the LLDD and to generate an optical signal that is representative of the driving signals.
Abstract: An embodiment includes a host-equalized optical transceiver. The host-equalized optical transceiver includes a driver analog interface, a linear laser diode driver (LLDD), and an optical transmitter. The driver analog interface is configured to interface with a host integrated circuit (IC) of a host system. The LLDD is directly electrically coupled to a host IC of the host system via the driver analog interface. The LLDD is configured to receive an equalized electrical data signal directly from the host IC via the driver analog interface and to generate a driving signal based on the equalized electrical data signal. The equalized electrical data signal is a linear signal. The optical transmitter is electrically coupled to the LLDD. The optical transmitter is configured to receive the driving signal from the LLDD and to generate an optical signal that is representative of the driving signal.
Patent•
29 Jul 2016TL;DR: In this paper, the first and second heat sink slide locks are configured to be respectively disposed beneath the first-and second housing slide locks when the heat sink is removably secured to the housing.
Abstract: An optoelectronic system includes an optoelectronic module and a heat sink. The optoelectronic module includes a housing and first and second housing slide locks. The first and second housing slide locks extend outward from opposite sides of the housing. The heat sink includes a heat sink bottom, first and second heat sink legs, and first and second heat sink slide locks. The first and second heat sink legs extend downward from opposite ends of the heat sink bottom. The first and second heat sink slide locks extend inward from the first and second heat sink legs. The heat sink bottom is configured to be in thermal contact with a housing top of the housing. Each of the first and second heat sink slide locks is configured to be respectively disposed beneath the first and second housing slide locks when the heat sink is removably secured to the housing.
1 Sep 2016
TL;DR: In this paper, the authors examine the process, current and voltage exposure to the devices as well as describes mitigation methods to reduce this current, which are applicable to many processes in semiconductor manufacturing and PCB assembly.
Abstract: Excessive ground currents expose sensitive devices to electrical overstress (EOS) in a hot bar soldering process. This paper examines the process, current and voltage exposure to the devices as well as describes mitigation methods to reduce this current, which are applicable to many processes in semiconductor manufacturing and PCB assembly.
Patent•
19 Dec 2016TL;DR: In this article, a transceiver connector may include a bottom-side connector, which includes a first ground pin adjacent to an edge of the bottom side connector, a first high-speed differential input pin adjacent with the first ground pins, a second ground pin with the second high speed differential input, a third ground pin and a fourth ground pin.
Abstract: A transceiver connector may include a bottomside connector. The bottomside connector may include a first ground pin adjacent to an edge of the bottomside connector, a first high-speed differential input pin adjacent to the first ground pin, a second high-speed differential input pin adjacent to the first high-speed differential input pin, a second ground pin adjacent to the second high-speed differential input pin, a serial interface data line pin adjacent to the second ground pin, a serial interface clock pin adjacent to the serial interface data line pin, a third ground pin adjacent to the serial interface clock pin, a first high-speed differential output pin adjacent to the third ground pin, a second high-speed differential output pin adjacent to the first high-speed differential output pin, and a fourth ground pin adjacent to the second high-speed differential output pin.
Patent•
18 Mar 2016TL;DR: In this paper, a transceiver can include a transmitter and a receiver, and the transmitter can include: a primary laser emitter, a primary monitor photodiode optically coupled with the primary laser, a spare laser, and a switch on the primary channel.
Abstract: A transceiver can include a transmitter and a receiver. The transmitter can include: a primary laser emitter; a primary monitor photodiode optically coupled with the laser emitter; a spare laser emitter; and a transmitter integrated circuit having a primary channel operably coupled with the primary laser emitter; a spare channel operably coupled with the spare laser emitter; a switch on the primary channel; and a secondary channel operably coupled with the switch and the spare channel The receiver can include: a primary detector photodiode; a spare detector photodiode; and a receiver integrated circuit a primary receiver channel operably coupled with the at least one primary detector photodiode; a spare receiver channel operably coupled with the spare detector photodiode; a receiver switch on the spare receiver channel; and a secondary receiver channel operably coupled with the receiver switch and the primary receiver channel.