FEMTOWHITE 800 - nonlinear supercontinuum device
The FEMTOWHITE 800 is a polarization-maintaning supercontinuum device for use with 800 nm femtosecond lasers. It contains 12 cm highly nonlinear, polarization-maintaning photonic crystal fiber with zero dispersion at 750 nm. The fiber ends are sealed and mounted in quartz ferrules, which are PM aligned to a line on the end of the device. The nonlinear fiber is mounted in a robust aluminum housing which can be easily mounted on a translation stage. The device features build-in beam expansion at the end facets, facilitating easy coupling and a high damage threshold.
The supercontinuum device has an outer diameter of 25 mm （~1 inch）, and is compatible with opto mechanics from e.g. Newport and Thorlabs.
- Optimized for 800-nm-range femtosecond pumping
- Polarization maintaining
- Zero dispersion at 750 nm
- Sealed and cleanable end-facets
- End-facet beam-expansion
- Highly nonlinear photonic crystal fiber technology
- Robust 25 mm （~1"） aluminum housing
- Compact: only 12 cm （4.7“） in length
- Compatible with standard holders
- Maintenance free
The FEMTOWHITE 800 is the equivalent to a nonlinear subassembly, and consequently, the performance of the device depends on the pump source. Below is shown a representative output spectrum from the PM fiber pumped by a 50 fs Coherent Mira laser at 800 nm.
Below is a schematic of the recommended setup for supercontinuum generation using the FEMTOWHITE 800. The fs pulses from the laser are launched through a Faraday isolator to avoid back reflections from the other optics and the FEMTOWHITE 800. For best performance （i.e. shortest pulses and highest peak power） it is recommended to use a prism compressor to compensate for the dispersion in the escope optics and the microscope objective. As the FEMTOWHITE 800 is polarization-maintaining, polarization control should be used to align the pump light polarization to one of the major axis in the device. Rough alignment can be accomplished using the guide line engraved on the end-facet of the device. Fine-tuning should be done by monitoring the degree of polarization of the output from the FEMTOWHITE 800. The device can also be used with unpolarized pump sources at the expense of slightly less broadening and randomly polarized output. Coupling into the device is best realized with a 40X or 60X achromatic microscope objective.