Example:
15 THz = 5.003461e+19 wavelength in petametres
1 THz = 3.335641e+18 wavelength in petametres | 1 wavelength in petametres = 2.997925e-19 THz
Conversion Steps:
15 × (1e+12 / 2.997925e-7) = 5.003461e+19