Cutting-edge Technologies

Transcription

1 Technologies in fields such as optical devices, material science, and information science, at the true cutting-edge of a new era. Contents H-CT-1 H-CT-2 H-CT-3 H-CT-4 H-CT-5 H-CT-6 H-CT-7 H-CT-8 H-CT-9 Zoom Microphone for Picking Up Distant Sounds Industrial-use Fuel-cell System for Reducing CO 2 Emission Compact and Functional Photonic Device Integration based on Silicon Photonics Ultrahigh-speed DAC for Optical Communications Systems Photonic Crystal Laser with Ultra-low Power-energy Cost Fast, Compact Random Number Generator Using Semiconductor Lasers Human Activity Recognition with Wrist-worn Sensor Device Atto-joule All-optical Switch ~Putting a Photonic Network into a Chip New Digital Processing Scheme Using Micromachine Technology

2 Microphone, Telecommunication, Highly realistic sensation Zoom Microphone for Picking Up Distant Sounds The zoom microphone can pick up distant sounds in analogy to a camera lens that can zoom in on distant targets. By locating a three-dimensional reflector near multiple microphones to collect spatially scattered sound energy, it is possible to pick up sounds from a specific distant target. This microphone will enable telecommunication services in which users can zoom in to video and pick up sounds at user-selected positions. It would also be useful for productions of highly realistic 3D video presentations and other high-resolution services that will become popular in the future. Soccer stadium Zoom in on specific players NTT Cyber Space Laboratories Zoom microphone The microphone can pick up distant sounds many meters away. Users can select any listening direction even though the equipment remains fixed. Multiple users can listen to sounds from different directions at the same time. It can re-pick up target sounds when multiple observed sounds have been recorded. Content delivery: Live broadcasts of sports such as soccer, American football and figure skating Free-viewpoint TV: TV Programs in which users select the viewing position and angle Hall acoustics: Enabling Q&A sessions without hand-held microphones Telepresence systems: Clearly capturing the speech of a specific speaker in a large conference room User s home Network Pass - Can pick up distant sounds - Can select any directions - Multiple users can listen to sounds from different directions H-CT-1

3 Industrial-use Fuel-cell System for Reducing CO 2 Emission Fuel cell, High-efficiency power generation, Ceramics Fuel cells efficiently convert energy stored in fuel into electricity. Based on NTT s own technology, cells (i.e., power-generation elements) and a laminated stack for housing them were developed. Moreover, in cooperation with the outside world, a fuel-cell system featuring the world s highest power-generation efficiency and lifetime was developed. These technologies contribute to reduction of CO 2 emission. (1) Development of cells - Planar cell with original materials - Durable fuel with high-efficiency power conversion - Increased cell diameter (to 12 cm) Cell Electrolyte Cathode NTT Environment Energy Systems Laboratories 12 cm (2) Development of stack Configuration that draws out cell performance Stack Ceramic cells that enable high- efficiently power generation Original electrode material that realizes longer lifetime Original stack configuration that draws out best cell performance Even higher efficiency by utilizing high-temperature exhaust heat Power can be supplied to telecommunications buildings and offices at high efficiency (low CO 2 -emission output level) Simultaneous supply of heat and power to schools and restaurants Anode (3) Development of power-generation module and system - Heat produced during power generation is applied for maintaining stack temperature, reformation reactions, and air preheating - Heat-insulated structure for suppressing heat release - Development of high-efficiency inverter Specification of fuel-cell system Items Value Dimension 1,500 (W) x 900 (D) x 1,800 (H) mm Weight 1,330 kg Output 0 kw - 5 kw Load following % Generation efficiency AC 45% (DC 54%) Fuel Town gas Fuel-cell System H-CT-2

4 Silicon photonics, Compact photonic device integration, Low-power photonic devices Compact and Functional Photonic Device Integration based on Silicon Photonics Silicon photonics technology enables high-productivity fabrication of ultra-compact photonic devices. We have used it to monolithically integrate various functional photonic devices on a silicon substrate. This technology can reduce the size and power consumption of photonic devices for telecommunications applications, and moreover, it can be applied to optical interconnections of LSI electronic circuits. Thus, it can help to reduce the costs and environmental loads in both future telecommunication networks and data centers that have to deal with huge amounts of data traffic. Ultra-fine silicon fabrication technology for making compact and low-loss wavelength filters Compact silicon semiconductor waveguide for dynamic photonic functions such as fast optical intensity adjustment and modulation Photo-detectors based on high-purity germanium grown on a silicon substrate (developed in collaboration with the University of Tokyo) Monolithic hetero-function integration on a silicon substrate Low power consumption through compact device integration Fast signal equalization of photonic nodes using multi-channel integrated VOA-PD *1 devices Low-power network operation with bandwidth control using compact WDM *2 receivers Large-capacity access networks using compact multi-channel transceivers with multilevel modulation formats Low-power LSI electronic circuits with on-chip optical interconnections *1 VOA-PD: Variable Optical Attenuator-Photodiode *2 WDM: Wavelength Division Multiplexing H-CT-3 Silicon photonics Compact and high productivity Economical and environmental Wavelength filter Single photonic device Ge-PD * Filter-VOA integration Fast VOA NTT Microsystem Integration Laboratories Photonic device integration Photonicselectronics integration VOA-PD integration Monolithic heterofunction integration on silicon wafer * Ge-PD: Germanium Photodiode

5 Ultrahigh-speed DAC for Optical Communications Systems Optical communications systems, DAC, InP HBT Digital coherent optical transmission schemes with advanced modulation formats, such as M-QAM* 1 and OFDM* 2, are promising techniques for constructing future beyond-100- Gbit/s/ch optical communications systems. In the transmitter for such systems, ultrahighspeed DACs* 3 are key components for generating complex modulated signals. NTT Laboratories have sophisticated ultrahigh-speed transistor, InP HBT* 4, technology and circuit design techniques, and have succeeded in developing ultrahigh-speed 6-bit DACs for such systems of the future. The first 6-bit DAC that can operate at a sampling rate above 30 GS/s Provides various modulated signals, such as M-QAM and OFDM Uses our in-house ultrahigh-speed transistor, InP HBT, technology Novel circuit design techniques for ultrahigh-speed and low-power operation Uses broadband packaging technique Ultrahigh-speed DAC InP HBT Emitter Collector Base f t =175 GHz f max =260 GHz Ultrahigh-speed transistor (InP HBT) DAC IC Transmitter using DACs (3mm x 3mm) Achieving both ultrahighspeed (> 30 GS/s) and low-power ( 1 W) NTT Photonics Laboratories DAC module Development of the packaging technique Future ultrahigh-speed and large-capacity optical communications systems (e.g. beyond-100-gbit/s/ch optical communications systems) Future ultrahigh-speed optical access systems Measurement tools (e.g. ultrahigh-speed arbitrary waveform generator) (e.g. 16-QAM signal generation) Digital signal processor (DSP) DAC DAC Laser diode Driver Driver Multilevel signal (Multilevel modulation) I Q 90 Optical I/Q Modulator 16-QAM *1 M-QAM: M-ary Quadrature Amplitude Modulation *2 OFDM: Orthogonal Frequency Division Multiplexing *3 DAC: Digital-to-Analog Converter *4 InP HBT: Indium Phosphide Heterojunction Bipolar Transistor H-CT-4 Adaptive to various modulation formats (M-QAM, OFDM, etc.) Utilization of various digital equalization techniques

6 Photonic Crystal Laser with Ultra-low Power-energy Cost Photonic crystal laser, Buried heterostructure Photonic crystal technologies enable us to make ultra-compact cavities with volumes less than 1 μm 3. A laser with an ultra-low threshold can be made by decreasing the cavity volume. Moreover, a photonic network chip, which is a hybrid integration with silicon CMOS *, must have appropriate output power for detecting the light at the photodetector and a high-speed direct modulation capability with very low power consumption. We have developed ultracompact buried heterostructure photonic crystal laser for such a purpose by employing the technologies of InP-based photonic integrated circuits. Photonic crystal Can construct ultracompact cavity less than 1 μm 3. Can strongly confine light NTT Photonincs Laboratories Buried heterostructure based on InP-based photonic integrated technologies Can confine carrier Can reduce thermal resistance Ultra-compact buried heterostructure photonic crystal laser with 5.0 x 0.3 x 0.15 μm 3 active region World s smallest buried heterostructure (5.0 x 0.3 x 0.15 μm 3 ) laser Ultralow threshold power (6.8 μw) and high output power (100 μw) achieved by optical pumping Extremely low energy consumption of direct modulated laser: 8.76 fj/bit for 20-Gbit/s direct modulation with clear eye-opening Next step in development: PhC laser using electrical pumping. High-density photonic integrated circuit Photonic network on chip: high-bandwidth density and reconfigurable photonic network on silicon CMOS CPU: continuous CMOS processor advances supported by energy-efficient optical system Green ICT: power efficient ICT equipment in data centers Other applications: ex. Ultra-small sensors requiring nano-scale light sources Active region (InGaAsP) 20 Gbit/s direct modulation 20 ps/div. Directly modulated photonic crystal laser with ultra-low power energy cost of less than 10 fj/bit. InP InP Active region Energy cost (fj/bit) 10 4 Waveguide-type laser VCSEL BH PhC laser Active volume (μm 3 ) * CMOS: Complementary Metal Oxide Semiconductor H-CT-5

7 Physical random number, Semiconductor laser, Integrated optical circuit Fast, Compact Random Number Generator Using Semiconductor Lasers Random number sequences that are absolutely unpredictable are essential for data security, so there is a demand for a compact device that rapidly generates random numbers on the basis of a physical phenomenon. Our work focused on the phenomenon in which the intensity of light from a laser varies randomly over time at high speed. We used the most advanced integrated optical circuit technology and high-frequency packaging technology to achieve a fast and compact random signal generator module. Digitizing the random output signal of the module can produce an unpredictable sequence of random numbers at high speed. Compact, integrated system by using integrated optical circuit technology Random number generation at 2.08 Gbit/s Physical guarantee that generated random number sequence cannot be predicted Password generation, encryption key generation Generation of random numbers required for the segmentation processing of secret data in secret sharing schemes Generation of key sequences in quantum cryptography Can also be used in numerical computation in science and engineering that uses random numbers NTT Communication Science Laboratories Mechanism of random signal generation Optical feedback laser Laser Light Mirror Unpredictable microscopic noise (Quantum noise) Waveform of laser output Macroscopic random signal The origin of randomness is quantum noise, which is unpredictable in principle. The quantum noise is rapidly amplified within a short time less than 0.5 ns due to instability nature of the optical feedback laser. Then it causes unpredictable and macroscopic random fluctuations in the laser output light, which is easily observable. Compact and fast random signal generator PD DFB SOA1 SOA2 Photograph of optical feedback laser chip (1 cm x 0.3 mm) 100 μm 2 cm Module with two built-in laser chips H-CT-6

8 Human Activity Recognition with Wrist-worn Sensor Device Wearable sensors, Activity recognition, Elderly care support Activity recognition technology is one of the most important technologies for lifelogging and the care of elderly persons. The recognition method proposed in this study recognizes what a user is doing by simply using a single wrist-worn sensor device. The device is equipped with a camera, a three-axis accelerometer, a microphone, a digital compass, and an illuminometer. The method recognizes the user s activities by employing objects the user is using, hand movements of the user, and sounds emitted in the activities. We sense user s daily activities by focusing on his/her hand, which is the part of the body most often involved in daily activities. We can recognize various activities with a single device. A camera on the wrist captures images of objects held in the hand. This permits us to recognize activities by using visual information of objects being held. We can preserve the user s privacy because our method recognizes activities by using abstracted image and sound information. Healthcare and care of elderly persons: Watch over elderly persons at a remote location Lifelogging: Making a continuous record of activities in daily life Context-aware services: Switch services automatically according to the user s activities Context-aware advertising: Recommend ads according to trends in daily activities MIC. Approach Basic idea Objects in use are strongly related to user s activities. Ex.: Use a tooth brush Brush teeth Example sensor data Cocoa Images Camera Concept NTT Communication Science Laboratories MIC. Camera: Color of objects + Accelerometer: Hand movement MIC.: Sounds of activities Camera Accelerometer Digital compass Illuminometer Prototype device Capture images of objects held in the hand Extraction Learn/ recognize activities Cup Acc. data Use cocoa Open fridge Use cup Stir cocoa Cyclic wave H-CT-7

9 Nanophotonics, Photonic integrated circuit, Photonic crystal Atto-joule All-optical Switch ~Putting a Photonic Network into a Chip Energy consumption and heat generation are becoming problematic issues in ICT, and it is expected that the introduction of photonic network technology into an information processing chip will help to alleviate them. Conventional photonic devices are too large and consume too much energy, and thus it is difficult to integrate many photonic devices in a chip at present. NTT Laboratories have built ultra-small all-optical switches that consumes an extremely small amount of energy, by employing a photonic crystal, which is an artificial dielectric structure with a periodic refractive index made by state-of-the-art nano-fabrication technology. We have demonstrated all-optical switching with a consumption energy of only 440 atto *1 joule, a record-low value. Photonic crystal that strongly confine light within a wavelength-sized volume. The all-optical switch with an ultrasmall photonic crystal nanocavity (0.02 μm 3 ). Highly integratable and ultrasmall device with ultralow energy consumption. All-optical switching of light signals by using a 440-atto joule control light pulse (less than 1/100th the energy of the previous record, Fig. 1). Alleviates trade-off between processing speed and energy consumption (Fig. 2). Capable of extracting pulse from a 40-Gbit/s pulse stream. Key device for large-scale photonic integration technology. Promising for large-scale photonic integrated circuit. High-speed information processing chips with ultralow energy consumption Useful for implementing large-scale photonic network technology in MPU *2 chips to drastically reduce the energy cost of information processing Integrated chips for routers, datacenters, and mobile terminals *1 atto: 1/10 18 *2 MPU: Micro Processing Unit H-CT-8 Input Pump Signal Switch -ON Switching time NTT Basic Research Laboratories, NTT Photonics Laboratories H0 nanocavity Line defect waveguide Wavelength 1 ns 100 ps 10 ps 1 ps 100 fs Switch -OFF This work Output InGaAsP slab Photonic crystal airholes (Energy x Time) Intensity (a.u.) Output Intensity PhC cavity 3 db Fig. 2 Comparison of all-optical switches Control pulse energy 420 aj db 35 ps Time (ps) Fig. 1 Photonic crystal all-optical switch PhC-MZI Ring Cavity 1 fj 1 pj 1 nj Switching energy per bit 660 aj SOA-MZI Nonlinear-fiber χ (3) ISBT waveguide

10 MEMS/NEMS, Micromachines, Semiconductor devices New Digital Processing Scheme Using Micromachine Technology We developed a novel digital processing method that involves vibrating a tiny doubly clumped beam oscillator fabricated with micromachine *1 technology. This method allows not only the fundamental logic operations of AND, OR, and XOR, but also multiple operations in parallel. To our knowledge, this is the first proposal for constructing a logic circuit from a single electromechanical device. The technique is potentially the key to constructing nanomachine computers that may lead to highly energy efficient and robust signal processing systems. The active element is a 250 μm-long, 85 μm-wide, and 1.4 μm-thick beam oscillator. The binary information is encoded as an oscillation with an amplitude of 10-8 m. Multiple channels of binary information are encoded as the oscillations at different frequencies. The function of parametric frequency conversion *2 can mix the input binary channels to construct all the primary logic gates. The multiple and parallel logic operations with multiple inputs and outputs are also possible. Highly energy-efficient and robust computer systems Ubiquitous systems requiring low power consumption Integration with highly sensitive MEMS sensors and optical devices *1 Micromachine (MEMS): Technologies to integrate micron-size mechanical devices on a chip using semiconductor microfabrication methods. *2 Parametric frequency conversion: A technique to generate difference or sum frequencies by mixing two oscillations with different frequencies. (A) Input A (frequency: f A ) Input B (frequency: f B ) The binary state is encoded as the oscillation amplitude (1) Input electrical signals applied Time (B) Oscillation amplitude NTT Basic Research Laboratories both A and B B only A only no input A and B A A or B (2) Mechanical beam oscillations B Output frequency (Hz) Output A or B (frequency: f D ) (A): Schematic drawing of parametric frequency conversion (B): Example of logic operations A B and or (3) Electrical signals at different frequencies Output A and B (frequency: f C ) H-CT-9