This dataset consists of optical photothermal infrared (O-PTIR) images of two lung cancer cells (H1299). The cells were fixed before imaging.

Enclosed files: 

• image_Fixed_LungCancer_cell1.cdf: hyperspectral image of cell 1
• image_Fixed_LungCancer_cell2.cdf: hyperspectral image of cell 2
• spectra.cdf: spectra of cell 2

All files are in netCDF format.

Hyperspectral images

The images have four dimensions 

• wavenumber: spectral axis
• x: fast axis
• y: slow axis
• trace_retrace: direction of movement during recording the image

The associated coordinates are: 

• xpix: pixel position in x
• ypix: pixel position in y
• trace: boolean trace/retrace
• pixel_size_X: size of pixel in x in nanometers
• pixel_size_Y: size of pixel in y in nanometers
• x_len: size along x in nanometers
• y_len: size along y in nanometers
• duty_cycle: duty cycle of laser during recording
• wavenumber: wavenumber of this image

Each image contains six channels which are 4D ( wavenumber, trace_retrace,y,x) 64 bit float arrays:

• X: lock-in amplifier X component
• Y: lock-in amplifier Y component
• auxin1: voltage corresponding to probe laser brightness
• power_x: lock-in X component of MCT detector signal
• power_y: lock-in Y component of MCT detector signal

The amplitude signal calculate from X and Y is the raw O-PTIR signal. It is normalized to the IR laser power by dividing by the amplitude of power_x and power_y and normalized to the sample transmission by dividing by auxin1. 

Spectra

The spectra have two dimensions 

• wn: spectral axis
• spec_index: spectral_index

The associated coordinates are: 

• wn: spectral axis in wavenumbers (cm⁻¹)
• pos_x: x position [nm]
• pos_y: y position [nm]

Each image contains six channels which are 4D ( wavenumber, trace_retrace,y,x) 64 bit float arrays:

• x: lock-in x channel
• y: lock-in y channel
• frequency: laser repetition rate in hertz
• phase: lock-in phase
• dio: ?
• trigger: ?
• auxin0: DC signal of ?
• amplitude: lock-in amplifier amplitude
• power: laser power