Our Team
Ewit Roos Partner & Co-founder
Ewit Roos General Partner & Co-Founder
Ewit Roos is General Partner and Co-Founder of PhotonVentures and Co-Founder of
PhotonDelta, where he served as CEO and led the development of the Dutch integrated
photonics ecosystem into one of the world’s leading photonic clusters. Under his leadership,
PhotonDelta secured €240M in initial funding and helped catalyze more than €1.1 billion in follow-
on public investment to accelerate the commercialization and industrialization of integrated
photonics technologies.
Through PhotonDelta, Ewit built a broad network of universities, research institutes, corporates,
investors and more than 60 partner companies across the photonics value chain. He played a key
role in the creation, funding, and scaling of numerous deep-tech photonics ventures, helping
establish the foundation for PhotonVentures as an independent venture capital firm in 2023.
At PhotonVentures, Ewit focuses on fund strategy, strategic partnerships, ecosystem
development, and portfolio value creation. Prior to PhotonDelta, he was Director at Brightmove
B.V., where he supported early-stage financing activities for more than 45 high-tech startups,
primarily at the Series A stage.
Ewit holds a management degree from Nyenrode Business University and a Master of Public
Administration from Erasmus University Rotterdam.
Rijkman Groenink General Partner & Co-Founder
Rijkman Groenink General Partner & Co-Founder
Rijkman Groenink is General Partner and Co-Founder at PhotonVentures and former CEO of
ABN AMRO, where he led the global strategy, international expansion, and major M&A
transactions of one of Europe’s largest financial institutions. During his tenure, he played a key
role in strengthening the bank’s international presence and creating substantial shareholder value
through strategic acquisitions and organizational transformation.
Following his executive banking career, Rijkman became active an active investor and
entrepreneur, co-founding private equity initiatives focused on renewable energy and other
international growth opportunities. Over the course of his career, he has built extensive
experience in capital allocation, corporate governance, board leadership and investment
oversight across both public and private markets.
At PhotonVentures, Rijkman contributes deep expertise in governance, institutional relationships,
strategic development and long-term value creation. His experience leading large-scale
organizations and investment activities provides valuable perspective in supporting the growth of
both the fund and its portfolio companies.
Rijkman holds degrees in Law and Business Administration.
Pieter Klinkert General Partner & Co-Founder
Pieter Klinkert General Partner & Co-Founder
Pieter Klinkert is General Partner and Co-Founder at PhotonVentures, bringing more than 20
years of experience across venture capital, entrepreneurship, business development and
company scaling. Prior to PhotonVentures, he held investment roles at Oost NL and PhotonDelta,
where he led multiple investments and worked closely with portfolio companies through growth
phases, strategic repositioning, and successful exits, achieving returns of up to 5x.
At PhotonVentures, Pieter leads deal execution, portfolio management, and company building,
with a strong hands-on focus on commercial strategy, organizational scaling, and follow-on
financing. He has extensive experience supporting deep tech ventures emerging from research
institutes, universities, and corporate innovation environments.
Combining investment expertise with operational and legal insight, Pieter works closely with
founders to accelerate commercialization, strengthen business fundamentals, and prepare
companies for future growth and financing milestones. He holds degrees in Law and Economics.
Joachim de Sterke General Partner & Co-Founder
Joachim de Sterke General Partner & Co-Founder
Joachim de Sterke is General Partner and Co-Founder of PhotonVentures and Co-Founder of
PhotonDelta, where he played a key role in building and financing the Dutch wafer-scale photonics
ecosystem. He led financial strategy, funding programs, and ecosystem investments, supporting
the deployment of more than €240M across the photonics value chain and helping establish the
Netherlands as a global leader in wafer-scale photonics innovation.
At PhotonVentures, Joachim leads fund strategy, capital allocation and portfolio development. He
brings extensive experience in venture building, M&A, fundraising and international growth. Prior
to PhotonVentures, he founded and scaled multiple venture-backed SaaS companies and
established the Creative Capital Studio investment platform, building a strong record as both
entrepreneur and investor.
Combining deep sector knowledge with hands-on operational experience, Joachim supports
portfolio companies through commercialization, international expansion, strategic partnerships
and follow-on financing. He holds an MSc in Finance from Erasmus University Rotterdam.
Evelien Talsma Investment Associate
Evelien Talsma Investment Associate
Evelien Talsma holds a Master’s degree in Nanobiology from TU Delft and a Bachelor’s degree in
law from Erasmus University Rotterdam, bringing a multidisciplinary perspective to the evaluation
of photonics and other deep-tech investment opportunities.
At PhotonVentures, Evelien supports deal sourcing, due diligence, and portfolio management
activities across the fund. She contributes to the technical, commercial, and strategic assessment
of investment opportunities and works closely with portfolio companies on value creation,
operational initiatives, and growth planning.
Her combination of scientific expertise and analytical rigor enables her to bridge technical
innovation and business execution, supporting founders in the development and scaling of
breakthrough technologies.
Jacqueline Tange Office Manager
Jacqueline Tange Office Manager
Jacqueline supports the operational management of PhotonVentures, coordinating internal
processes, investor-facing activities, events, and communications to ensure the efficient
functioning of the firm.
She brings extensive experience across operations, executive support, investor relations, and
marketing. Throughout her career, she has supported executive teams and boards, managed
investor programs, and coordinated complex organizational and communication activities.
Combining a hands-on approach with strong organizational and communication skills, Jacqueline
plays a key role in supporting the investment team and the continued growth of PhotonVentures.
Flo Pattiwael Principal
Flo Pattiwael Principal
At PhotonVentures, Flo Pattiwael leads investment sourcing, execution, and portfolio value
creation activities across the fund. He plays a central role in deal origination, due diligence,
transaction structuring, investment analysis, and investment decision-making. In addition, he is
actively involved in investor relations and fundraising efforts. He also works closely with portfolio
companies on strategic development, scaling initiatives, and follow-on financing.
Prior to joining PhotonVentures, Flo Pattiwael gained investment experience at PGGM
Investment Management, where he worked across investments, strategy, and ESG initiatives. .
Flo combines strong analytical capabilities with a hands-on approach to supporting founders and
identifying emerging opportunities in wafer-scale photonics and deep technology. He holds a Cum
Laude MSc in Finance & Investments from Rotterdam School of Management (RSM).
Casper Vissers Investment Associate
Casper Vissers Investment Associate
Casper Vissers holds a Master’s degrees in Financial Econometrics from VU Amsterdam and
Aerospace Engineering from TU Delft, combining strong quantitative and technical expertise to
support investments in photonics and other deep-tech sectors.
At PhotonVentures, Casper supports deal sourcing, due diligence, and portfolio management
activities across the fund. He contributes to the technical, commercial, and financial assessment
of investment opportunities and works closely with portfolio companies on value creation,
strategic initiatives, and growth planning.
His multidisciplinary background enables him to bridge advanced technology and investment
analysis, supporting founders in the development and scaling of innovative deep-tech companies.