Showed first, ultrabright single photon source at 1550 nm. Sandwiched colloidal quantum dots in a nanogap cavity to enhance their spontaneous emission rate ~10,000-times. This resulted in single photon emission count rates of 12.6 MHz for quantum dots emitting at 1550 nm and 15 MHz for quantum dots emitting at 1350 nm, corresponding to an improvement of more than two orders of magnitude over state-of-the-art. (Under review, (2024)).