A 635 nm linearly polarized laser
(Coherent Cube) is coupled to the microscope using a single-mode fiber
(P3-405BPM-FC-2, Thorlabs), which is then focused down onto the nanoparticles
through a 100× objective (Olympus, NA = 0.8). The irradiation
duration and power are varied to tailor the polymerization conditions.
For laser-wavelength-tuned irradiation, we use an optical parametric
oscillator pumped by a Ti:sapphire laser (Spectra Physics MaiTai delivering
200 fs pulses, 10 nm line width, at 80 MHz repetition rate), which
drives the OPO (Spectra Physics Inspire), with average output powers
of tens of mW. By means of a tunable optical filter, the average power
of the laser beam is kept below 30 μW on the sample focal spot.
(Coherent Cube) is coupled to the microscope using a single-mode fiber
(P3-405BPM-FC-2, Thorlabs), which is then focused down onto the nanoparticles
through a 100× objective (Olympus, NA = 0.8). The irradiation
duration and power are varied to tailor the polymerization conditions.
For laser-wavelength-tuned irradiation, we use an optical parametric
oscillator pumped by a Ti:sapphire laser (Spectra Physics MaiTai delivering
200 fs pulses, 10 nm line width, at 80 MHz repetition rate), which
drives the OPO (Spectra Physics Inspire), with average output powers
of tens of mW. By means of a tunable optical filter, the average power
of the laser beam is kept below 30 μW on the sample focal spot.