Two million mirrors,
one decision.
Post-Quantum Tek steers data between fibers with a hologram instead of a mirror. No electronics in the path, and a thousand times faster than the mirror-tilt optical switches shipping today.
Switch light with light.
How it is done today
Data moves between racks as light in fiber, but the switches that route it are electronic. At every hop the light is detected, turned into electrons, switched, and re-emitted by a laser. Each conversion costs energy and makes heat, and that heat has to be removed with more air conditioning, more water, and more electricity.
Even the optical switches hyperscalers already use are slow. They tilt tiny mirrors, and a mirror takes ten to twenty-five milliseconds to settle: fine for rewiring a cluster between jobs, far too slow to follow traffic.
How the PQT-HOS does it
The PQT-HOS is patented technology, invented at the University of Arizona and licensed exclusively to Post-Quantum Tek. It steers light with a diffraction pattern written on a micromirror array. The pattern is the switch. Rewriting it takes microseconds, the light never stops being light, and there is nothing in the path to get hot.
It is a circuit switch, not a packet switch. An electronic switch forwards every packet in nanoseconds and will keep that job; the price of its speed is a conversion at every hop. A circuit switch holds a light path open for the elephants, the large, long-lived flows that carry most of a cluster's bytes, and leaves the mice to electronics. And because it only steers light and never reads it, it is independent of data rate and protocol. A fabric built on it carries next year's transceivers without being replaced.
Twelve microseconds.
Among optical circuit switches, time is the differentiator, so here it is on one axis. The diffractive switch is finished before your eye registers it. The mirror-based switch is still settling when the sweep restarts.
Electronic packet switches are faster still, in nanoseconds per packet. They are not the comparison. The PQT-HOS replaces the millisecond optical circuit switches in a fabric's spine, not the packet switches at its leaves.
Energy, in three honest numbers.
Not "100x." A chain, each link measured, from one switch to a whole facility. The full model, with every source, is on the energy page.
picojoules per bit to cross an electrical switch with its optics, versus an optical circuit switch. Nvidia SN5610 at 2,080 W; Google Palomar at 108 W.
of network power removed when Google replaced its spine with optical switching. Measured in production, SIGCOMM 2022.
of a facility's IT load, and through PUE the same share of its electricity, cooling, and water. Networking is 4.5% of US data center electricity and up to 8% in an AI cluster.
Measured, then designed.
The first column is what peer-reviewed prototypes did. The second is what the next chip is designed to do. We keep them separate.
| Bench prototypes, measured | Next-generation chip, designed | Shipping optical circuit switches | |
|---|---|---|---|
| Ports per switch | 7×7 and 32×32 built | thousands | 136 to 576 |
| Reconfiguration | 12 µs | about 10 µs | 10 to 25 ms |
| Insertion loss | 6.5 dB optics plus 10 dB diffraction | 3 dB | 2 dB or less |
| Switch electronics | about 12 W, from part datasheets | about 12 W | 45 to 140 W |
| Data rate | Independent of rate and format; 25 Gbaud QPSK passed with no degradation | Independent | |
Sources and footnotes are on the science page.
One chip, five network functions.
Because the switch is a hologram and not a mirror, the same pattern that aims the light can do things a mirror cannot. Each of these is described in the patent.
Switch
Any input to any output, all inputs at once, with no blocking. Each input lights its own region of the array and is re-aimed independently, so changing one path never interrupts another.
Multicast
A pattern can form more than one spot. One input can be sent to several outputs simultaneously, which is what a collective operation in an AI cluster asks for.
Monitor
A defined fraction of any signal can be diverted to a detector for in-line monitoring, provisioned on demand and removed when not needed.
Balance
The pattern sets how much light reaches each output, so per-port attenuation for signal balancing is built in, with no extra component.
Self-align
Temperature drift and mechanical creep are corrected by recomputing the pattern, not by touching the optics. The switch realigns itself.
Survive
The signal is spread across tens of thousands of mirrors. Losing 2.5% of them costs 0.25 dB. There is no servo loop to fail, and no single mirror whose failure takes down a port.
From the Wyant College of Optical Sciences.
Patented technology, invented at the University of Arizona, one of the world's leading optics schools, and exclusively licensed to Post-Quantum Tek through Tech Launch Arizona.
Patent
US 9,453,970, "Reconfigurable diffractive optical switch," and divisional US 9,726,827, issued to the Arizona Board of Regents.
Published
Eight peer-reviewed papers from 2013 to 2017, including work with Microsoft Research and UC Berkeley, and a three-rack testbed at Microsoft Research.
Inventors
Pierre-Alexandre Blanche, Nasser Peyghambarian, and Brittany Lynn. Dr. Blanche, an Optica Fellow, is PQT's Founding Investigator.
Where we are
Tucson, Arizona. Bench-proven, and raising to build the commercial prototype with an engineering partner.
Built for fabrics that cannot slow down.
AI and HPC clusters
Reconfigure the fabric between training phases instead of over-provisioning for the worst case. Microsecond switching keeps up with collective operations, not just job scheduling.
Hyperscale data centers
Fewer, larger switches with no electrical conversion cut the network's share of power and cooling. Rate-independent switching means the fabric survives the next transceiver generation.
Research and government networks
National labs, universities, and test facilities that need high port counts, fast reconfiguration, and low heat in constrained rooms.