Diode Laser Engineer (f/m/d)

Focused Energy is a fusion energy startup with the goal of generating unlimited clean energy to responsibly meet future global demand. With the use and commercialization of laser-induced inertial fusion, a clean and highly efficient power generation technology is coming within reach, suitable to ensure a secure and scalable future energy supply. We are seeking a skilled and driven Diode Laser Engineer to help design, qualify, and scale the high-power diode laser technologies that will power our next-generation fusion laser systems. In this role, you will work at the intersection of physics, engineering, and industrialization — partnering closely with suppliers, research institutions, and internal system teams to advance the performance, reliability, and manufacturability of laser diode technologies. What you’ll do: Diode Technology Development: Design and evaluate high-power laser diode emitters, bars, and stacks to meet demanding performance, efficiency, lifetime, and cost targets for fusion laser applications. Testing & Characterization: Develop and execute comprehensive electro-optical, thermal, and reliability test protocols (P-I-V, spectral behavior, beam quality, thermal resistance, lifetime, etc.) under relevant operating conditions including pulsed, CW, and high-duty-cycle regimes. Automated Test Infrastructure: Design, commission, and operate automated test benches for high-volume characterization and accelerated life testing of commercial and custom laser diode devices. Reliability & Lifetime Modeling: Lead accelerated life testing (ALT / HALT), analyze degradation mechanisms and failure modes, and build predictive lifetime and reliability models to inform system design and operational limits. Supplier & Partner Collaboration: Work closely with industry partners, suppliers, national labs, and academic groups to improve diode performance, packaging, thermal management, and manufacturing readiness. System Integration: Collaborate with DPSSL system and beamline teams to ensure diode technologies integrate effectively into laser modules and support overall system performance and scalability. Data Analysis & Reporting: Analyze large experimental datasets, generate rigorous technical documentation, and communicate findings and recommendations clearly to internal teams and external partners. Who you are: PhD (or equivalent experience) in optical, electrical, mechanical engineering, physics, or a related field, with deep experience in semiconductor laser physics, epitaxy, packaging, and/or device characterization. Proven experience designing, building, and operating laser diode test and characterization setups, including optical, thermal, and electrical diagnostics. Strong understanding of thermal management, reliability physics, degradation mechanisms, and lifetime testing methodologies for high-power semiconductor devices. Comfortable working with large experimental datasets, applying statistical and modeling tools to extract insights, predict performance, and guide engineering decisions. Able to work effectively across internal system teams and with external suppliers, academic collaborators, and industrial partners in complex, multi-stakeholder environments. You naturally think about how component-level decisions affect system-level performance, cost, scalability, and long-term operational viability. Preferred: Experience working with diode-pumped solid-state lasers (DPSSL), high-average-power laser systems, or adjacent fields such as industrial lasers, photonics manufacturing, or fusion/energy systems. Preferred: Experience with thermal, optical, or reliability modeling tools to complement experimental work and support predictive design and scaling. What we offer: Innovative Technology & Mission: Be part of a cutting-edge company working on groundbreaking research in clean energy and scientific discovery. Career Development: We invest in our people. This is an opportunity to join an early, growing company at the forefront of new technology, where you’ll have the opportunity to develop and grow your career. Collaborative Culture: Work with great people in a dynamic, international environment with top-tier scientists, engineers and professionals passionate about solving global challenges. Ownership: Take ownership from day 1 and drive impact by making decisions, solving challenges and shaping the future of our company. Your Success is our Success: We offer a competitive salary and company ownership in the form of stock options, giving you a direct stake in our success and ownership in what we build together. Vacation Days: We support your work-life-balance by granting you 30 days of vacation per year. Flexibility: We believe work should adapt to your life—not the other way around. That’s why we offer a hybrid setup, giving you the freedom to work from our office while also enjoying the flexibility to work from home when it suits you. Snacks and Drinks: Our office fridges are never empty. Enjoy our healthy snacks and drinks. Our Darmstadt office even offers a subsidized canteen with delicious lunch options daily. Retirement Plan: If you decide for a private pension plan, we will finance 15% on top of your monthly contributions. Equipment: Choose between a state-of-the-art Windows or Apple Laptop. In addition, you will receive a keyboard, mouse and headset so you are fully equipped from day 1. Events: We organize regular events to foster team bonding, encourage collaboration, and build a strong, supportive company culture. Connect with colleagues across departments, share ideas, and have fun together, both in and outside of the workplace. Mobility with NAVIT: We partner with NAVIT to support your flexible commuting needs—whether it’s a public transportation ticket, taxi rides or car-sharing you choose what fits your lifestyle. Fitness with Wellhub: We care about your health. Get access to a wide range of gyms, fitness studios and wellness services across Europe through our partnership with Wellhub. Focused Energy is an equal opportunity employer committed to creating an inclusive environment. Qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender perception or identity, national origin, age, marital status, protected veteran status, or disability status. Pursuant to the San Francisco Fair Chance Ordinance, Focused Energy will consider for employment qualified applicants with arrest and conviction records. Compensation offered will be determined by factors such as location, level, job-related knowledge, skills, and experience. Certain roles may be eligible for incentive compensation, equity, benefits.