This paper presents a silicon photonic temperature sensor based on a complementary metal-oxide-semiconductor (CMOS) compatible cladding-modulated (CladMod) grating design on the silicon-on-insulator platform. The resulting device achieves narrow-band reflection (Δλ = 0.63 nm), a high extinction ratio (21 dB), high temperature sensitivity (83.4 pm/°C), and a wide temperature-sensing range. More importantly, this grating design allows stable reflection bandwidth $\rm{(\Delta \lambda / \Delta W}_{\rm{g}}\,\rm{ = 0.013)}$ , Bragg wavelength $\rm{(\lambda }_{\rm{B }}\rm{/ \Delta W}_{\rm{g}}\,\rm{ = 0.002)}$ , and temperature sensitivity $\rm{(\delta \lambda / \delta T/ \Delta W}_{\rm{g}}\,\rm{ = - 1.3\times 10}^{- 5}\rm{ K}^{- 1}\rm{)}$ against variations in grating width. This level of temperature-sensing performance is difficult to achieve using a strip/slab-type grating or microring resonator. The CladMod gratings were further implemented on a polysilicon gate in a standard bulk CMOS process, thereby enabling integration with other microelectronic devices to serve as an on-chip distributed temperature-sensing element This approach shows considerable promise for applications such as future photonic-electronic integrated circuits requiring in situ temperature monitoring for wavelength stabilization, or high-temperature microelectronics where silicon bandgap temperature sensors are unable to operate properly
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