Ultra-sensitive absorption microscope

Our unique and completely new label-free microscope makes minuscule absorption of single nanoscale particles and defects visible, pushing the sensitivity of conventional absorption measurements by a factor of 1000. This enables research, process optimization and quality control in nanotechnology, material science, and the life sciences on a new level.



Our fundamentally new microscopy technique enables detection and characterization of many nanoscale materials for the first time


Reveal weak absorption signals and map tiny variations in absorption and discover so far invisible optical properties and distributions in nanoscale matter.


Measure absolute absorption and scattering cross sections of nanoscale matter.

Spectrally resolved

Perform absorption spectroscopy at the parts-per-billion level on individual nanosystems (absorption below 0.0001% can be measured).

Fast imaging & time resolved measurements

Absorption on the parts-per-million level can be imaged in real-time. Furthermore, time resolved measurements at a single point can be performed with 1µs time resolution.


A large variety of materials can be imaged and measured in our microscope and be prepared using spin-coating, drop casting, stamping, ....


Absolute absorption cross sections of atomistic defects can be measured

Carbon nanotubes 

Visualize and perform absorption spectroscopy on single carbon nanotubes

2D materials

See variations of absorption, scattering and polarization on 0.0001% levels in atomically thin materials 

Your material

Contact us to get new insights into your material and your research area!

Tissue & Sections 

Image few nm-thick sections of human tissue or ultra-thin sections of cells. 


Measure presence, spectra, distribution and location of nanoparticles, e.g. nm-sized gold or Perovskites.

Technology: Scanning cavity microscopy


We place the sample between two ultra-high reflective mirros. Light is reflected between these two mirrors and passes the sample up to 100 000 times. This way minuscule variatios in absorption, refractive index or polarization get amplified and can be made visible for the first time.


Our measurement method is highly sensitive to

  1. Absorption
  2. Scattering
  3. Refractive index
  4. Polarization

and can do all this spectrally resolved for fingerprinting.

Scanning cavity technology

How our scanning cavity microscope works:

  1. Microscopy fiber mirror probe mirror
  2. Planar sample holder mirror
  3. Place sample
  4. Scan to image the sample.
  5. Do spectroscopy.
  6. Publish!
  7. Repeat

Resonator-Enhanced Absorption Microscopy

A detailed description can be found in the Article Seeing the unseen: Boosted absorption imaging and spectroscopy using a scanning microresonator.

Optical resonators consist of two opposing highly reflective mirrors, between which light forms a standing wave. In other words, light travels back and forth up to a million times before exiting the resonator. As a result, the interaction between light and matter within this resonator can be amplified by many orders of magnitude. Pioneered in quantum optics, this technology is known for its ultra-sensitive sensing capability since the many roundtrips of the light in the resonator enhance various photophysical processes (e.g. absorption, fluorescence, scattering and dispersion) [4]. Nonetheless, the large resonator mode of conventional Fabry-Perot cavities and the lack of control over its position relative to the sample, make them unsuitable for imaging.

This limitation was overcome by the invention of microscopic mirrors. These atomically smooth concave micromirrors are typically fabricated by laser ablation on the end facet of an optical fiber which is subsequently coated with a highly reflective dielectric coating. Combined with a planar macroscopic sample mirror at a distance of only a few micrometers, a resonator is formed. This yields an almost diffraction-limited mode waist on the surface of the planar mirror and thereby offers the spatial resolution required for imaging. Scanning the micromirror over the macroscopic mirror, an image of the sample can be obtained, where light has interacted with the sample several thousands of times within each pixel. Due to the many round trips of the light in the resonator, even weakly absorbing nanoscale objects on the sample mirror lead to an easily detectable reduction in the resonator transmission, making even minuscule absorption (0.0001%) visible.