Integrated Optics - Applied Optics Fundamentals and Device Applications - page 220

8

7

6

N D = 2 × 10 17 cm -3

5

N D = 3 × 10 17 cm -3

4

N D = 5 × 10 17 cm -3

3

N D = 8 × 10 17 cm -3

N D = 2 × 10 17 cm -3

N D = 11 × 10 17 cm -3

2

N D = 8 × 10 17 cm -3

1

N D = 5 × 10 17 cm -3

N D = 11 × 10 17 cm -3

0 1 1.5 2 2.5 3

Aspect ratio

FIGURE 5.10
λ 0 = 1.3 μm—Maximum range of thickness for guiding only the E E

x

1 ⋅ modes.

y

11

through e). Accurate control of the guide separation is very important since
the coupling length L decreases exponentially with the ratio c/e 5 , where e 5 is
the transverse mode extinction coefficient. In fact, for separations C < e 5 there
will be a significant perturbation upon the optical mode field profile by each
channel upon the other. Predictions of the coupling length for separations
less than e 5 , therefore, would require a more extensive analysis of the per-
turbation effect.