3D printed dual wavelength wavefront sensor

Wavefront sensor are able to measure phase and intensity of light. It is used to characterize laser beams or to characterize aberration of imaging systems. The most common approach is to put array on micro-lenses in front of camera at the focal distance. The positions of focal spots then define a gradient of the wavefront of incident light. This type of sensor is called Hartmann-Shack-Sensor.

We have the possibility to fabricate various micro optics components such as lenses,prism, gratings as well as free form components with a sufficient optical quality. This is done by two-photon polymerisation 3D print. This gives freedom to come up with new optical components.

In this project we designed an array on microlenses merged with optical gratings. We were able to fabricate such array directly on camera chips. The resulting device is a combination of wavefront sensor with a spectrometer. It is able to measure the wavefront of the incident light as well as its wavelength. Due to this ability we demonstrated that such device is able to measure wavefront of two spectrally different incident light simultaneously.

Left - commerical low-cost camera, which is used for the dual wavelength wavefront sensor. top - zoom image on the camera chip with the printed microlens array. bottom - SEM images of single microlenses

Selected References

Yu, Z. Design and Fabrication of Microoptical Elementes via 3D Direct Laser Writing, MSc. Thesis, FSU Jena, 2023