Ultracompact CMOS-compatible optical logic using carrier depletion in microdisk resonators

Abstract

We present a CMOS-compatible optoelectronic directed logic architecture that achieves high computational throughput (number of operations per second per unit area) by its ultracompact form factor. High speed-to-power performance is also achieved, by the low capacitance and high junction-to-mode overlap of low-radii SOI vertical pn junction microdisk switches. By using wavelength-division multiplexing and two electrical control signals per disk, each switch performs (N)OR, (N)AND, and X(N)OR operations simultaneously. Connecting multiple switches together, we demonstrate higher-order scalability in five fundamental N-bit logic circuits: AND/OR gates, adders, comparators, encoders, and decoders. To the best of our knowledge, these circuits achieve the lowest footprint of silicon-based multigigabit-per-second optical logic devices in literature.

Wavelength-division-multiplexing (WDM)-based integrated electronic–photonic switching network (EPSN) for high-speed data processing and transportation

“…Large-bit size instruction in required in commercial CPUs. For instance, 2 24 addresses are needed if the address codes of the microprocessor are 3 bytes (24 bits), which is common in modern commercial CPUs [35]. To replace electrical counterparts, we should design the EPSN that is capable of operating on large bit numbers such as 16 (2 bytes) or 24 (3 bytes).…”

“…The proposed N−2 N optical decoder utilizes light to transport information in the optical path in subpicoseconds, which is one or two magnitudes faster than electrical gates [36]. The time latency of an N-bit (N = m + n) decoder includes the EO time constant of the modulator τ eo , the latency of electrical signal τ g , the latency of each optical gate τ o , the optoelectronic transition time for PDs τ oe .…”

“…Most of them are available from the foundries currently. Then, optical digital logic gates [16][17][18][19] and basic arithmetic units, including but not limited to adders [20,21], comparators [22,23], encoders [4], and decoders [24], are designed. They are all essential parts of an arithmetic logic unit (ALU) [25].…”

Ultrafast electro-optical disk modulators for logic, communications, optical repeaters, and wavelength converters

“…The microdisk resonator has several advantages over the microring resonator. The disk configuration is more efficient for hosting vertical pn junctions [15,24,25]. Furthermore, as detailed in Ref.…”

Toward High‐Speed and Energy‐Efficient Computing: A WDM‐Based Scalable On‐Chip Silicon Integrated Optical Comparator

“…Abundant passive and active building blocks for digital optical computing and interconnects on integrated photonic platforms have been experimentally demonstrated and have been provided by foundries, such as electro‐optic (EO) switches and modulators. [ 14–17 ] Digital logic gates [ 18–21 ] and basic digital logic modules including but not limited to adders, [ 22–24 ] comparators, [ 25 ] encoders, [ 12 ] and decoders [ 26 ] have been investigated in previous studies. Furthermore, logic synthesis specified for photonic circuits has been proposed for designing more complicated computing modules with a high bit size.…”