Lucplanfln 40

The beam used for PAE is derived from a Ti:sapphire laser (Spectra Physics Mai Tai) and polarized along the horizontal axis of the pBNA structure. Before coupling to the microscope, the laser beam is reflected by a pair of galvo mirrors which are operated for beam steering by Labview (National Instruments Corporation), a data acquisition and instrument control platform58 (link). The galvo driver is connected to a DAQ board (NI USB-6221) with the position of the mirrors controlled by the output voltage. A 0.6-NA, collar-adjustable microscope objective (Olympus LUCPlanFLN × 40) is used to focus the incident laser beam onto the plane of the pBNA structure, which is placed on the sample stage of a standard microscope. A white-light source (Ocean Optics HL-2000) with an approximate bandwidth over 400–1,000 nm is used to measure the reflectance of the doubly heterogeneous nanoantenna arrays.

For lasing experiments, an optical parametric amplifier (Spirit-OPA + Spirit-OPA-UV3, Newport Corporation) was pumped by a fully automated ultrafast laser system (Spirit One 1040–8, 8 W at 1040 nm, Newport Corporation), which was used for generating the excitation pulse (1 kHz, 480 nm, pulse width < 400 fs). The incident laser was coupled to a microscope (IX71, Olympus) for focusing on crystals through an objective lens (Olympus LUCPlanFL N ×40, numerical aperture = 0.60). The PL signal from the sample was then focused and collected by a fibre optic spectrometer (PG2000-Pro, Ideaoptics Instruments).