Table 1.

Comparison of miniature reported photonic-based microwave oscillators.

Phase noise
			SSB phase noise (dBc/Hz, scaled to 15.2 GHz)		Refs. #
Material	Configuration	Carrier freq. (GHz)	1 kHz	100 kHz
SiO2 (this work)	Bright soliton	15.2	−90	−140
MgF2	Bright soliton	14.1	−121	−155	35
Si3N4	Bright soliton	19.6	−82	−132	7
Si3N4	Dark soliton	5.4	−76	−131	8
SiO2	SBS	21.7	−71	−113	10
Si3N4	SBS	21.8	−55	−102	13
Chalcogenide-on-silicon	SBS	40.0	−93	−110	52

Relative Allan deviation
Material	Configuration	Min. Adev. gate time (ms)	Min. Adev.	Adev. @ 1 s	Refs. #
SiO2 (this work)	Bright soliton	50	6 × 10−11	2 × 10−10
MgF2	Bright soliton	200	5 × 10−12	10−11	4
Si3N4	Bright soliton	1	3 × 10−9	8 × 10−8	7
SiO2	SBS	20	10−9	10−8	10

Performance of an on-chip silica bright soliton microcomb (this work), a Crystalline bright soliton microcomb^4,35, a Si₃N₄ bright soliton microcomb⁷, a Si₃N₄ dark soliton microcomb⁸, a SiO₂ Brillouin laser¹⁰, a Si₃N₄ Brillouin laser¹³, and a hybrid electric-Brillouin oscillator⁵².