Page 178 - Tunable Lasers Handbook

4 CO, Isotope lasers and Their Applications 157

TUNABLE DIODE MICROWAVE LOCAL
LASER OSCILLATOR

HgCdTe VARACTOR INTERMEDIATE
PHOTODIODE FREOUENCY
DETECTOR AMPLIFIER

MICROWAVE
ABSORPTION SPECTRUM

MONOCHROMATOR
FIGURE 25 High-accuracy calibration method for heterodyne spectroscopy with tunable
lasers. In the figure, wavy and solid lines denote optical and electrical paths, respectively. (Reprinted
with permission from Freed [75]. 0 1982 IEEE.)

FIGURE 26 The 6775-MHz beat note of a l4CI6o2 laser (0@1)--[1@0,0200] I-band P-uansi-
tion and a diode laser tuned to an ammonia absorption line at 12.1 pm. (Reprinted with permission
from Freed [75]. 0 1982 IEEE.)