For VNIR:
60 nm
70 nm
60 nm
125 nm

For SWIR:
30 000 nm
40 000 nm
40 000 nm
40 000 nm
40 000 nm
40 000 nm
50 000 nm
70 000 nm

And the FWHM are the same after Radiometric Calibration. And after the layer stacking and the conversion to BIL.

Yes it's the WV-3 sensor.

Can you post the .hdr file of the file you input to FLAASH?

ENVI
description = {
Create Layer File Result [Mon Jan 22 10:40:58 2018] [Mon Jan 22 10:45:44
2018]}
samples = 5035
lines = 7769
bands = 12
header offset = 0
file type = ENVI Standard
data type = 4
interleave = bil
sensor type = Unknown
byte order = 0
map info = {Geographic Lat/Lon, 1.0000, 1.0000, -72.38558037, -14.91943857, 1.8580000000e-005, 1.8060000000e-005, WGS-84, units=Degrees}
coordinate system string = {GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]]}
wavelength units = Nanometers
data ignore value = 0.00000000e+000
band names = {
Layer (Blue:Peru_VNIR_RadCal.dat),
Layer (Green:Peru_VNIR_RadCal.dat),
Layer (Red:Peru_VNIR_RadCal.dat),
Layer (NIR1:Peru_VNIR_RadCal.dat),
Layer (Band 1:Peru_SWIR_RadCal.dat),
Layer (Band 2:Peru_SWIR_RadCal.dat),
Layer (Band 3:Peru_SWIR_RadCal.dat),
Layer (Band 4:Peru_SWIR_RadCal.dat),
Layer (Band 5:Peru_SWIR_RadCal.dat),
Layer (Band 6:Peru_SWIR_RadCal.dat),
Layer (Band 7:Peru_SWIR_RadCal.dat),
Layer (Band 8:Peru_SWIR_RadCal.dat)}
wavelength = {
480.000000, 545.000000, 660.000000, 832.500000, 1209.100008, 1571.599960,
1661.100030, 1729.500055, 2163.700104, 2202.199936, 2259.299994, 2329.200029}
fwhm = {
60.000000, 70.000000, 60.000000, 125.000000, 30000.000000,
40000.000000, 40000.000000, 40000.000000, 40000.000000, 40000.000000,
50000.000000, 70000.000000}

It shows in your header that the fwhm are very large values for SWIR:
fwhm = {
60.000000, 70.000000, 60.000000, 125.000000, 30000.000000,
40000.000000, 40000.000000, 40000.000000, 40000.000000, 40000.000000,
50000.000000, 70000.000000}

Did you manually enter these? You can edit them via View Header->Edit Header to be the appropriate values.

It seems that a problem occurs with the unit of FWHM values. In the raw data it's from 30-70nm but in the file I used, it's 30-70um...

I will modify that. Thanks !