How High Can You Go?

Leigh Klotz WA5ZNU, <leigh@wa5znu.org>

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How High is 474 THz?

144-148 Mhz is 2 meters
802.11b WiFi is 2.4 Ghz, or 2400 MHz is 12.5cm (also a ham band)
Police Radar and Motions Detectors are 10 Ghz, 3cm (also a ham band)
Around 30 Ghz (1cm), neutral gas in the atmosphere has significant attenuation
47 Ghz (0.6cm) (also a ham band): millimeter waves begin about here
300 Ghz (1mm) -- no licenses from here on up; severe attenuation
10 Thz (0.01mm) -- Far InfraRed or Sub-Millimeter; attenuation slackens
60 Thz-300 Thz (5uM to 1uM) -- Infrared, with peaks and valleys of attenuation
400Thz - 1000Thz (0.75uM - 0.10 uM) -- magic rainbow of atmospheric transparency
400 Thz (0.75uM = 750nM) -- we call this "red"
474 THz (632 nM) -- Helium-Neon red lasers
440-480 THz (625-680 nM) -- cheap read laser diodes