Minimization of Heating Power for Thermooptic Waveguide Type Devices

Abstract

Thennal analysis ofthemlOoptic device IIsing planar optical wllvegllide structures is perjonned by using implicit finite difference method. lsothenllal profiles of the medium having the core and cladding are shown from the computation results. We have proposed two new structures where lower heatil/g power is required whel/ compared to that of the conventiol/a/ structure. A compromise between heating power and response time is made for different applica/iollS of themlOoptic devices.

Polarization-Insensitive Thermo-Optic Mach Zehnder Device Based on Silicon Oxinitride Waveguide with Fast Response Time

“…Thermal analysis of conventional and other thermo-optic structures with a silicon trench and optimized device parameters, such as heater width, total cladding width, trench width, etc., have already been studied [15]. As in these structures, the proposed delay line structure has two waveguides with the addition of a groove of width W G and depth H G made in between two waveguide cores and two other side grooves of width W G =2 and height H G for the release of stress anisotropy, which mainly induces a refractive index increase in TM polarization [7,12].…”

“…In the proposed structure, the bottom and right side surfaces of the trench portion are attached to the substrate, whereas the left side surface of the trench is attached to the heat insulator. The position of waveguide cores and their sizes, heater size and its position, upper cladding thickness W oc , total cladding thickness W c , trench width W T , and thickness H T are kept same as those of the conventional structure [15]. Both side surfaces of the proposed structure are assumed as heat insulators for suppressing lateral heat diffusion.…”

“…The phase change is determined from Eq. (1) by the calculated temperature difference T c using the implicit finite difference method [15] for a heating power P . The heating power required to get T c can be expressed as P D q 0 :W H :L H (where q 0 is the heat flux of the heater).…”

Tunable Optical Add/Drop Multiplexers Using Cascaded Mach Zehnder Coupler

“…Table 1. We have already proposed and studied low power thermooptic MZ (with equal arms) structure [16] which reduces heating power for device operation by 1.5 times in comparison to conventional structure. Figure 5a shows crosssectional view of conventional thermooptic delay line structure of width W wg and cladding width W c consisting of two SiON/SiO 2 waveguides of core width w and thin film heater of width W H placed on the larger arm of delay line to obtain the refractive index difference between the cores, having separation W s after heating.…”

“…The position of waveguide cores and their sizes, heater size, and its position, upper cladding thickness W oc and total cladding thickness W c are kept the same as those of the conventional structure. The implicit Table 1 Heating power of conventional structure and proposed structure-1 finite difference method is used for the estimation of the heating power, P to get T c between two waveguides for both the conventional thermooptic planer structure and low power thermooptic structure [16]. The heating power required for different thermooptic phase changes Â.P / in the conventional structure and proposed structure-1 is shown in Table 1.…”