CTO / Chief Photonics Officer (Stealth Photonic Bio-sensing Venture) in London

We are an early-stage deep-tech photonic bio-sensing company combining silicon photonics, micro-fluidics, and applied AI to bring high-end optical instrumentation out of the central lab and onto a low-cost disposable chip plus a compact reader. The first product is a point-of-care diagnostic targeting a multi-billion-dollar market currently served by hand-aligned, six-figure bench-top instruments.

The mission is to transform a 500K benchtop optical instrument into a 5 disposable chip. The optics, the photonics, the detection, and the entire signal path that today sits inside hand-aligned six-figure machines must live on a wafer that ships to a clinic and gets thrown away. Silicon photonics has finally reached the cost-volume curve where this is feasible, and AI design tools are finally good enough to do the multi-physics co-optimisation without an army of PhDs.

Your role involves owning the photonic and detection stack from architecture through foundry to a working integrated reader. You will be the technical anchor who turns design intent into manufacturable, clinical-grade silicon, and ultimately the person who decides which physics gambits ship and which we leave for the next product.

Responsibilities:

• Photonic and detection architecture for the disposable chip and reader.
• Foundry execution: PIC, nano-optical, and microfluidic prototyping relationships; tapeout cadence; yield, robustness, and tolerance management.
• The design loop: working alongside our automated multi-physics design engine; interrogating its output, catching unphysical behaviour, and driving design-arounds.
• Reader integration: opto-mechanical, thermal, and electronics integration with the cartridge.
• Risk register: what fails, how often, how we engineer it out for a device that has to be manufacturable at scale.
• Hiring: your network is part of the value you bring for the first technical hires (micro-fluidics, hardware/firmware, instrumentation).

London-based. Hybrid works well. Fully remote isn’t a fit at this stage, we need to be in the same room when it matters.

Your profile:

• PhD in silicon photonics or EE, demonstrable experience taking PIC designs to working silicon.
• Have personally taken multiple designs from layout to working silicon at a commercial photonics foundry.
• Comfortable across photonic integration, photon-counting detection, and nano-optical component design.
• Reads simulation and optimiser output as a co-pilot, not a black box.
• Bonus: prior experience in scientific instrumentation, bio-photonics, or biomedical optical engineering.

Qualities we are looking for:

• Intellectually honest about uncertainty. Hardware is a humbling teacher. The right answer when you don’t know is “I don’t know”, followed by an experiment.
• Comfortable being the deepest expert in the room. You will be the photonics authority for investors, partners, and the technical organisation we hire after you.
• Sceptical of black-box AI on physics problems. You will work alongside an automated multi-physics design engine, treating its output as a smart collaborator that occasionally produces unphysical nonsense, not as oracle.
• Bias to ship, not polish. First-silicon is rarely perfect. We learn from the chip we have, not the chip we wish we had.
• Direct communication. Founding team disagreements get aired and resolved on the day. We trade weeks for clarity.
• Long-horizon patience. A six-figure instrument compressed onto a 5 chip is not a one year project. We are building for a decade.

What we offer:

• Founding team-level equity. Salary set at pre-seed close, calibrated to the round size and the role’s market reality at that point.

Who you’d be working with:

Prathap, the founder. Repeat founder and AI expert, London-based. Software engineer by training, hardware startup founder by choice, pulled into life-sciences instrumentation because lab-on-a-chip is the wedge that puts cutting-edge diagnostics into the hands of the half of humanity that doesn’t have access to a teaching hospital. Built the multi-physics BO engine that produced the current tape-out candidate, drafted the priority patent specification, and owns GTM, funding, and the early organisation.

I’m not a silicon-photonics engineer. Fab, foundry, opto-mechanical integration, these are the parts of the device I can’t run myself, and I’m not planning to. They’re the parts you’d own end-to-end: architecture, foundry choice, tape-out cadence, the technical hires. I’d back your calls, not second-guess them.

How we work:

• Done > perfect. A prototype on the bench is worth a thousand-slide deck.
• Outcome > metrics > intuition. Metrics are how we navigate; outcomes are what we are navigating to; intuition is what we tolerate when neither is available.
• A bad decision is better than no decision. Founding teams die of indecision more often than bad calls.
• Over-communicate by default. Ambiguity within the founding team is the single biggest unforced error early.
• Compassion and trust over performance incentives. Compensation gets people in the door; trust keeps them building.

We are an equal-opportunity employer and value diversity. We consider all applications equally regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, or gender identity. We strongly encourage individuals from groups traditionally underrepresented in tech to apply.