g2-Zero

What g2-Zero does

g2-Zero is a privately held quantum-hardware spin-off of the Spanish National Research Council (CSIC), established in 2022 and headquartered in Madrid with a clean-room engineering facility on the Cantoblanco campus. The company designs and manufactures electrically driven, deterministic single-photon sources packaged as single-mode fiber-pigtailed optoelectronic devices. Its technology is based on a CSIC patent (licensed to g2-Zero in 2022) covering the electrical driving and tuning of quantum emitters, fabricated using well-known semiconductor materials and wafer-level processes — analogous to LED manufacturing — to enable mass production rather than laboratory-grade one-offs.

The company's product line is a single integrated hardware device, marketed as a Plug and Play single photon source: high-brightness, high-purity single photons delivered on demand (one photon per electrical pulse), vibration-resistant, maintenance-free, and integrable with photonic integrated circuits and standard cryostats. g2-Zero targets four vertical segments: government and defense (quantum key distribution and quantum networks), quantum computing (photonic quantum computing platforms), quantum sensing and metrology, and academic and corporate quantum-photonics research. The company sells via direct enterprise field sales to quantum research institutions, government agencies, defense organizations, and corporate R&D divisions, operating a B2B model rather than a self-serve channel.

Revenue is generated primarily through hardware sales of single-photon-source devices, with licensing and technology transfer of the CSIC patent positioned as a potential secondary stream. Pricing is not publicly disclosed. Capital sources include non-dilutive Spanish and EU grants (NEOTEC/CDTI 2021 onward) and a €315,000 pre-seed equity round in April 2024 led by FI Group with participation from Hamamatsu Photonics CV and business angels, for cumulative funding above €1 million since 2021. Strategic positioning is reinforced by selection into the inaugural NATO DIANA cohort (2023) and by participation in the MadQuantum Business Ventures accelerator and the ESA Business Incubation Centre (2025).

Name

g2-Zero

Legal name

G2ZERO S.L.

Website

https://g2-zero.com

Company type

Private

Founded year

2022

Operating status

Operating

Headcount range

1–10 employees

Short description

g2-Zero is a CSIC spin-off that designs and manufactures electrically driven, deterministic single-photon sources for quantum communications, computing, and sensing, selling fiber-pigtailed hardware devices to research institutions, government, and defense customers.

Ownership category

akta.pro rank

Product category

Quantum Photonics Hardware

NAICS

Semiconductor and Related Device Manufacturing (334413)

SIC

Optical Instruments & Lenses (3827), Semiconductors & Related Devices (3674)

akta.pro primary industry

Quantum Photonics & Quantum Imaging (Single-Photon, Lidar, Ghost Imaging) (HDAGAHAF)

akta.pro secondary industries

Quantum Sensor Components & Subsystems (Lasers, Vacuum, Photonics, Diamond/NV, MEMS) (HDAGAHAM), Quantum Transceivers, Modems & Photonic Interfaces (HDAGAFAE)

Keywords

• Single photon sources
• Quantum photonics hardware
• Quantum key distribution devices
• Deterministic photon emitters
• Quantum semiconductor components

Headquarters

HQ city

Madrid

HQ country

Spain

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Technology or R&D, Operations, Infrastructure, Supply Chain, Marketing or Sales

Revenue model

1. Single Photon Source Devices: g2-Zero generates revenue from the sale of its deterministic single photon source devices — compact, electrically driven, fiber-pigtailed packages sold to quantum research institutions, government agencies, defense organizations, and corporate R&D. The model is product-based with enterprise-level transactions, likely recurring as customers expand quantum infrastructure.
2. Licensing and Technology Transfer: Revenue may be generated through technology licensing arrangements stemming from the CSIC patent, as the company was founded on acquiring the patent license for the quantum light source technology.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels5 records

Core offering

g2-Zero develops and sells deterministic, electrically driven single photon source devices for quantum communications, computing and sensing applications. The product is a fiber-pigtailed, alignment-free semiconductor device packaged at wafer level that emits exactly one photon per electrical pulse, targeting enterprise and institutional buyers in government, defense, academic, and corporate quantum R&D.

Product overview

g2-Zero offers a single unified product line: deterministic single photon sources based on proprietary quantum semiconductor technology. Their Plug and Play sources generate high-brightness, high-purity single photons on demand via purely electrical operation, packaged in a compact optoelectronic format with single mode fiber coupling. The product is designed for mass production using wafer-level semiconductor fabrication processes, targeting quantum communications (QKD), photonic quantum computing, and quantum sensing applications. There are no separate modules, add-ons, or platform components—the offering is a single integrated hardware device delivered as a table-top unit with control electronics.

Differentiator

Problem solved

Functional benefit

Products and services

• Plug and Play Single Photon Sources A deterministic, on-demand single photon source device that emits one photon per electrical pulse. It operates like an LED powered only by electricity, with a single-mode fiber-pigtailed package, no required optical alignments, and vibration-resistant maintenance-free operation. Designed for quantum communications (QKD), photonic quantum computing (qubits), and quantum sensing/metrology applications, and built using wafer-level semiconductor fabrication processes that enable mass production. Intended for institutional and enterprise quantum buyers (government/defense, quantum computing labs, academic and corporate R&D).

Quantifiable outcome

• Deterministic single photon emission: one photon per electrical pulse
• +1 more outcomes

Segments4 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Four partnerships are on record, tiered core and flagship.

• MadQuantum Business VenturescoreStrategic or Co-development Partner · 1 January 2025g2-Zero joined the MadQuantum Business Ventures accelerator in 2025, gaining access to mentorship, market development resources, and quantum industry networks in Madrid and beyond.
• European Space Agency (ESA) Business Incubation CentrecoreStrategic or Co-development Partner · 1 January 2025g2-Zero joined ESA's Business Incubation Centre in 2025, providing the company with resources, infrastructure, and market access for space-related quantum photonics applications.
• NATO DIANAflagshipStrategic or Co-development Partner · 1 January 2023g2-Zero was selected from over 1,300 applications as one of 44 spin-offs in the first NATO DIANA (Defence Innovation Accelerator for the North Atlantic) cohort. The program supports dual-use quantum and photonics technologies for transatlantic security applications, providing g2-Zero with strategic visibility, mentorship, and defense-sector ecosystem access.
• CSIC (Spanish National Research Council)flagshipTechnology or Integration · 1 January 2022g2-Zero is a spin-off from CSIC. In 2022, the company acquired the license for CSIC's quantum light source patent, which forms the core of its technology. This relationship provides ongoing access to CSIC's research capabilities and quantum photonics expertise.

Scale indicators7 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• ID Quantique: Swiss leader in quantum-safe network encryption and quantum sensing solutions, offering QKD systems, quantum random number generators, and single photon detection. Comparable to g2-Zero as a buyer of single photon sources and as a peer in the broader quantum communications stack.
• PsiQuantum: US-based photonic quantum computing company building utility-scale quantum computers using single photons and silicon photonics. Adjacent comparable to g2-Zero on the photonic quantum computing customer segment and on the use of single photons as qubits.
• Xanadu Quantum Technologies: Canadian photonic quantum computing company developing squeezed-light and Gaussian boson sampling quantum processors. Comparable to g2-Zero as a buyer of quantum photonic components and as a peer in the photonic quantum computing ecosystem.
• Toshiba Quantum: Toshiba's quantum technology division develops QKD systems and quantum communication networks globally. Comparable to g2-Zero as a strategic buyer of single photon sources and as a downstream integrator serving the same government/defense and telecom quantum communications end markets.

Emerging players

• Qunnect: US-based quantum networking company building entanglement-based quantum communication hardware, including single photon sources and quantum memory for distributed quantum networks. Overlaps with g2-Zero on the quantum communications side and shares the deterministic photon-source technology focus.
• TundraSystems Global: European developer of true single photon sources for quantum communications and quantum cryptography. Comparable as a smaller European startup targeting the same QKD and quantum communications buyer segments with similar single photon source hardware.
• Single Quantum: Dutch company developing single photon detectors (superconducting nanowire) for quantum communications, computing, and sensing. Complementary rather than directly competing, but serves the same enterprise quantum customers and ecosystem.

Direct peers

• Sparrow Quantum: Danish spin-off developing deterministic single photon sources based on quantum dot technology for quantum cryptography and photonic quantum computing. Closely comparable to g2-Zero as a European deep-tech startup commercializing quantum-dot-based single photon sources to research and enterprise quantum buyers.
• Quandela: French semiconductor-based single photon source company spun off from CNRS, offering deterministic quantum dot and resonator-based photon sources for quantum communications and computing. Most directly comparable to g2-Zero in technology (deterministic single photons), product format (fiber-pigtailed sources), and target markets (QKD, photonic quantum computing, sensing).

Others

• Hamamatsu Photonics: Japanese photonics instrumentation giant that is both a strategic investor in g2-Zero and a manufacturer of detectors, light sources, and photonic devices. Comparable as a deep photonics strategic partner with potential overlap in single photon detection and broader quantum photonic instrumentation.

Market position

Strengths4 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights6 records

Customer concentration

• LinkedInlinkedin.com/company/g2-zero

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles9 records

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about g2-Zero