Yoshiharu Tashiro

Double heterostructure optoelectronic switch as a dynamic memory with low‐power consumption

A pnn double heterostructure optoelectronic switch with dual extractor electrodes was dynamically operated as an optical memory with the resulting achievement of 20 μW holding power. This value represents a reduction in holding power of about three orders of magnitude as compared to that of conventional light‐emitting optical bistable devices. Complete operation, involving optical writing, regeneration, and high‐speed erasing of written data through a dual extractor‐electrodes configuration, was carried out with a simple driving scheme.

Vertical to surface transmission electrophotonic device with selectable output light channels

A photoeletronic bistable device with selectable light output channels has been fabricated for implementation in photonic switching and processing systems. The device is a variation of the vertical to surface transmission electrophotonic device. Output in the stimulated light emission mode was successfully obtained from different waveguide channels by external electronic switching. Output channels could be switched at a rate of 400 Mb/s. The potential versatility of this device has been experimentally confirmed in programmable or switchable optical interconnections.

Reconfigurable optical interconnection using a two‐dimensional vertical to surface transmission electrophotonic device array

A dynamic reconfiguration of optical interconnections for enhanced flexibility in photonic switching systems is realized using a two‐dimensional vertical to surface transmission electrophotonic (VSTEP) device array. A matrix operational scheme for the VSTEP array is proposed and demonstrated. Through this operation, functions for light emission and for electrically programmable spatial light modulation are obtained in a single chip of the VSTEP array and a high‐speed electronic addressing of 1 ns per one line for the matrix is also confirmed.

High Speed Response in Optoelectronic Gated Thyristor

High speed response in a three terminal pnpn double heterostructure optoelectronic gated thyristor is demonstrated. The gate electrode on the active layer is operated to sweep out excess carriers in the active layer. The turn-off delay time has been measured to be 5 ns, which is two orders of magnitude improvement compared with that for the two terminal mode operation. Furthermore, it has been shown that the turn-off delay time cannot be estimated from the conventional 90-10% fall time.

Optical Crossbar Interconnection Using Vertical-To-Surface Transmission Electro-Photonic Devices (Vstep)

A new optical interconnection is proposed, using one dimensional electro-photonic semiconductor arrays (vertical-to-surface transmission electro-photonic devices). It realizes variable interconnection, signal summation and thresholding functions for optical neural networks and parallel processing. Experimental results showed 8 Mbps data rate operations and certified the interconnection feasibility.

Surface‐emitting GaAs/AlGaAs lasers with dry‐etched 45° total reflection mirrors

Surface‐emitting GaAs/AlGaAs lasers with 45° total reflection mirrors have been successfully produced using a 45° tilted reactive ion beam etching technique. The ratio of surface‐emitted light output power to edge‐emitted light output power was obtained at values as high as 77%. The total reflection mirror was formed within 1° of the desired precise 45° angle. This type of surface‐emitting laser is promising for optoelectronic integrated circuits because of the simplicity of its structure and fabrication.

High-mobility two-dimensional electron gas in modulation-doped InAlAs/InGaAs heterostructures

Abstract The two-dimensional electron gas (2DEG) mobilities in MBE-grown modulation-doped InAlAs/InGaAs heterostructures have been studied. For the MBE growth, the flux intensity transients were minimized by adopting specially designed cell-shutters, which ensured highly abrupt heterointerfaces. A low temperature 2DEG mobility as high as 110000 cm2/V s has been achieved with an optimized layer structure. The 2DEG mobilities are discussed in relation with relevant scattering mechanisms.

Vertical to Surface Transmission Electro-Photonic Device for the Application of Optical Interconnection and Processing

Electro-photonic incorporation in the VSTEp reconfiguration of optical interconnectio significant function in optical switching and It is because non-linear characteristics controllable in the VSTEP. Variable optical i example of the dynamic reconfiguration, has achieved in a pnpn-VSTEP array through a matr speed electric addressing of Ins per one confi rmed. permits a dynamic nS, which is a computing systems. are electrically nterconnection, one been successfully ix operation. Highelement has been

Cascade-connective optical parallel logic processor using electrophotonic devices

To perform image or arithmetic processing optically, it is necessary that a large number of required optical processors be connected in a series. For such cascade connections, however, coding and decoding processes are undesirable because of the necessity for the complicated hardware that often results. We propose here a new logic algorithm for application to cascade connections, which utilizes, in place of coding and decoding processes, true logic signals and their complements. Its optical implementation is also discussed. A processing module is constructed from electro-photonic devices referred to as vertical to surface transmission electro-photonic devices, a ferroelectrical liquid-crystal spatial light modulator, and a planar microlens array. Its logic operations are successfully demonstrated.