Senior Scientist - Precision Measurements (Optical Metrology)

About Xanadu: 

Xanadu’s mission is to build quantum computers that are useful and available to people everywhere.
At Xanadu, we are learners, innovators, researchers, collaborators and problem solvers. We are creating something that has never been built before.  What we are doing is extremely hard, the classic moon shot. Few people in their life will be able to be a part of something like this, where if we are successful, the technologies we develop will solve some of the world’s most challenging problems and literally change the world. And that is something to be excited about!

Your role and responsibilities: 

As a Senior Scientist - Precision Measurements , you will contribute your expertise in precision measurements for optical detector metrology to further the performance and scalability of our Superconducting Nanowire Single Photon Detector (SNSPD) platform. As part of the Low Temperature Devices team, you will take ownership of the development, implementation, and deployment of an ultra-high-accuracy system detection efficiency (SDE) metrology capability for our SNSPD-based detectors.

You will be responsible for designing and validating a near-infrared optical metrology system that sets new standards in stability, repeatability, and accuracy. This includes full system optimization including component selection, control, monitoring, data analysis and integration within our cryogenic detector infrastructure. Working with a cryogenic radiometer, you will be tasked with measuring record-breaking uncertainties of fiber-coupled single-photon detectors in the near infra-red, developing a world-leading standard. 

This role demands deep experience with device precision measurements, exceptional attention to detail, and a strong foundation in detector physics and optical metrology. You will ensure that our SDE measurements are not only accurate, but scalable and production-ready. 

Responsibilities include: 

• Lead the implementation of an ultra-high-accuracy metrology system for measuring SNSPD system detection efficiency at near-infrared wavelengths 
• Integrate and operate a cryogenic radiometer as an optical power reference standard 
• Perform detailed cryostat-based SNSPD characterization to validate performance, repeatability, and long-term stability of SDE measurements
• Identify and resolve subtle system-level effects that influence detection efficiency, such as thermal drifts, and background noise suppression 
• Define measurement protocols and statistical analysis pipelines to support rigorous validation of large-scale detector array performance 
• Interface with internal teams and external collaborators 
• Contribute to pushing the state-of-the-art in precision measurement for single-photon detectors 

Basic qualifications and experience: 

• PhD in Physics, Electrical/Mechanical Engineering, or a related field, with at least 2 years of postdoctoral or industry experience 
• Proven track record in high-precision measurement, metrology, or detector calibration 
• Extreme attention to detail and a systematic approach to experimentation, with a focus on minimizing both systematic and statistical errors — essential qualities for high-precision metrology. 
• Familiarity with fiber-coupled optical systems 
• Excellent interpersonal and written communication skills 
• Comfortable working both independently and collaboratively on multidisciplinary hardware projects in a dynamic environment 

Preferred qualifications and experience: 

• Experience with Python-based lab automation or data acquisition 
• Familiarity with SNSPD, TES, MKID, or other cryogenic detector technologies
• Experience with analog test equipment (e.g., SMU, VNA, photodetectors) 
• CAD and simulation experience for optical, thermal, or mechanical design (e.g., SolidWorks, COMSOL, Zemax) 
• Hands-on experience with cryogenic systems (4K or colder), including cooldown, troubleshooting, and maintenance 
• Proficient with a wide range of photonic equipment, including Optical Spectrum Analyzers (OSA), polarization controllers, DFB lasers, fiber-based mode-locked lasers, optical modulators, and attenuators. 

This is for a new position. Your base salary will be determined based on your location, experience, and internal benchmarks. The base salary range is 150,000 - 200,000 CAD. You will also be eligible for equity and benefits.