2. Research
  3. Quantum Technology
  4. Quantum Photonic Components
  5. Micro-Integration Technology

Micro-Integration Technology

We turn the design of our photonic modules into very compact and robust hardware by utilizing our proprietary hybrid micro-integration technology. It is based on solder and adhesive bonding of electronic, opto-electronic, micro-mechanical and micro-optical components with ultra-high precision to carriers or very stable miniature optical benches. Our activities cover the development of proper robotic integration facilities that allow for simultaneous active alignment of multiple components with nm-resolution, the development of assembly processes, the acceptance tests for all critical components, the actual assembly, the validation of the electro-optic performance of the photonic modules and, finally, integration of the photonics modules at our partner's premesis. Depending on the project requirements we establish proper product assurance measures, specifically for the assembly of space hardware.

Compact laser module during ultra-precise hybrid micro-integration.

The robotic integration facility is based on piezo-driven, ultra-high resolution (1 nm, 1 µrad) manipulators. We currently operate setups that handle up to four components simultaneously and control the position and orientation of the latter in 18 degrees of freedom in an ISO 5 class environment. To find the optimal aligment of a set of miniature components, their positions and orientations are varried simultaneously and specific parameters, e.g. optical power, polarization state, optical emission spectrum or optical phase noise are monitored. After finishing the alignment, the optical components are adhesively bonded with UV-curing or hybrid adhesives to a miniature optical bench.

We continuously refine our micro-integration setup and processes to improve quality and reliabilty of the photonic modules. Proper measures include partial automation, specifically the simultaneous alignment of multiple degrees of freedom based on AI optimization methods, and integration of collaborative robots into the integration facility in order to provide a very flexible, tele-robotic, partially automated integration facility utilizing industry 4.0 concepts.

Robotic integration setup configured with manipulators to control the position and orientation of four components with a total of 18 degrees of freedom. © Jan Baumann (FBH)
Hybrid micro-integrated DFB-MOPA laser module. These modules form the starting point of our developments and are used, among other things, in Bose-Einstein condensate experiments in the drop tower in Bremen. © FBH/schurian.com
Hybrid micro-integrated DFB-MOPA laser module with electrical interface. These modules enable high-frequency modulation of the injection current through the integrated electrical interface. Modules of this type were used in the generation of the first Bose-Einstein condensate in space. © FBH/schurian.com
Zoom into a micro-integrated laser module consisting of a DFB master ozcillator and a power amplifier. The center shows the DFB laser chip with Au bond wires. Micro-lenses and a miniature optical isolator are loated to the left.
Extended cavity diode laser with integrated semiconductor optical amplifier. On May 13, 2018, a laser module of this type was used in the JoKaRUS experiment of German Aerospace Center DLR to realize the first iodine-based precision optical frequency reference in space, on board a sounding rocket. Similar modules will be used for precision spectroscopy and Bose-Einstein condensation experiments not only on sounding rocket missions but also on the International Space Station (ISS). © FBH/schurian.com
Hybrid micro-integrated spectroscopy module in a housing. This fiber-coupled module features an integrated rubidium vapor cell, phase modulator and photodiodes to enable frequency modulation or modulation transfer spectroscopy and thus frequency stabilization to an atomic transition. © FBH/N. Vlach
Custom design isolated coaxial feedthroughs (3 ADC, 65 GHz signal bandwidth) for an hermetic package.
Miniature thermo-electrics cooler with integrated temperature sensor used to control the temperature if volume holographic gratings with high precision.
Ferrule carrying focussing optics and a ploarization maintaining single mode optical fiber for fiber coupling on the miniature optical bench.
Magnet for a miniature optical isolator. The magento-optical crystal is located on top.