Erratapage 1454 and 1455

In the Bell System Technical Journal, 56, No. 8 (October 1977), Figs. 2 and 3 on pp. 1454 and 1455 should appear as follows. ELEMENT 2 X / 4 LINE I ELEMENT 1 GRATING IS i r ELEMENT 3 GRATING 4fU(a) I 0 IS --I t: m T 3 o -4 FREQUENCY (150 kHz/div.) 4 NORMALIZED FREQUENCY, A (b) (c) Fig. 2--(a) Diagram of a grating resonator in the external transmission configuration, (b) The transmission spectrum at ~145.5 MHz for a resonator on YZ-LiNb03 using Tidiffused gratings with A = 12 ^m and L = 6.481 mm. (c) The calculated transmission spectrum for the device in (b) using k = 3.74 cm - and a = 0.036 cm - 1 .