US 12,218,157 B2 · Optical receiver comprising monolithically integrated photodiode and transimpedance amplifier

Abstract

An optical receiver comprises a monolithically integrated pin photodiode (PIN) and transimpedance amplifier (TIA). The TIA comprises InP heterojunction bipolar transistors (HBT) fabricated from a first plurality of layers of an epitaxial layer stack grown on a SI:InP substrate; the PIN is fabricated from a second plurality of layers of the epitaxial layer stack. The p-contact of the PIN is directly connected to the input of the TIA to reduce PIN capacitance CPIN. The TIA capacitance CTIA may be matched to CPIN. Device parameters comprising: a thickness of the absorption layer, window area, and an optional mirror thickness of the PIN; device capacitance CPIN+CTIA; and feedback resistance RF of the TIA; are optimized to performance specifications comprising a specified sensitivity and responsivity at an operational wavelength. This design approach enables cost-effective fabrication an integrated PIN-TIA, for applications such as a 1577 nm receiver for an ONU for 10G-PON.

Claims32

Dependent claims

An optical receiver comprising a monolithically integrated photodiode (PD) and transimpedance amplifier (TIA), wherein:

an epitaxial layer stack is formed on a semi-insulating indium phosphide (SI:InP) substrate;
the TIA comprises InP heterojunction bipolar transistors (HBT) formed by a first plurality of semiconductor layers of the epitaxial layer stack formed on the SI:InP substrate;
the PD comprises a p-i-n diode (PIN) formed by a second plurality of semiconductor layers of the epitaxial layer stack, comprising an n-layer, an i-layer and a p-layer, the second plurality of semiconductor layers being formed on top of the first plurality of semiconductor layers of the epitaxial layer stack;
a p-contact of the PIN is directly interconnected by a conductive trace to an input of the TIA, to provide a device capacitance CPIN of the PIN, and a capacitance CTIA of the TIA;
and
device parameters comprising values of:
CPIN, CTIA, a thickness ti of the i-layer, an area of the PIN;
and a transimpedance feedback resistance RF of the TIA are selected to provide an integrated PIN-TIA meeting performance specifications comprising a specified sensitivity and responsivity at an operational wavelength.

5 more elements

Dependencies are inferred from the claim text.

Optical receiver comprising monolithically integrated photodiode and transimpedance amplifier

Life of this patent

Optical receiver comprising monolithically integrated photodiode and transimpedance amplifier

Life of this patent

Abstract

Claims32