Electrophotonic-ic Inc.

William A Hagley

Gudmundur A Hjartarson

Lawrence E Tarof

John William Mitchell Rogers

Electro-absorption modulators (EAM) and monolithically integrated electro-absorption modulated lasers (EML) and methods of fabrication are disclosed. Vertically stacked waveguides for a distributed feedback (DFB) laser, an electro-absorption modulator (EAM) and a passive output waveguide are vertically integrated, and the DFB laser, EAM and output waveguide are optically coupled using laterally tapered vertical optical couplers. Laterally tapered vertical optical couplers provide an alternative to conventional butt-coupling of a laser and EAM, offering improved reliability for high power operation over extended lifetimes. The EML may comprise monolithically integrated electronic circuitry, e.g., driver and control electronics for the DFB laser and EAM. Beneficially, integrated EAM driver and control circuitry comprises a high-speed electro-optical control loop for very high-speed linearization and temperature compensation, e.g. to enable advanced modulation schemes, such as PAM-4 and DP-QPSK, for analog optical data center interconnect applications. Some embodiments are compatible with fabrication using a single epitaxial growth.

Vertically integrated electro-absorption modulated lasers and methods of fabrication

Electro-absorption modulators (EAM) and monolithically integrated electro-absorption modulated lasers (EML) and methods of fabrication are disclosed. Vertically stacked waveguides for a distributed feedback (DFB) laser, an electro-absorption modulator (EAM) and a passive output waveguide are vertically integrated, and the DFB laser, EAM and output waveguide are optically coupled using laterally tapered vertical optical couplers. Laterally tapered vertical optical couplers provides an alternative to conventional butt-coupling of a laser and EAM, offering improved reliability for high power operation over extended lifetimes. Optionally, the EML comprises monolithically integrated electronic circuitry, e.g., driver and control electronics for the DFB laser and EAM. Beneficially, integrated EAM driver and control circuitry comprises a high-speed electro-optical control loop for very high-speed linearization and temperature compensation, e.g. to enable advanced modulation schemes, such as PAM-4 and DP-QPSK, for analog optical data center interconnect applications. Some embodiments are compatible with fabrication using a single epitaxial growth.

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 C. The TIA capacitance Cmay be matched to C. Device parameters comprising: a thickness of the absorption layer, window area, and an optional mirror thickness of the PIN; device capacitance C+C; and feedback resistance Rof 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.

Optical receiver comprising monolithically integrated photodiode and transimpedance amplifier

An electro-absorption modulator (EAM) comprising an integrated high speed electro-optical control loop for very high-speed linearization and temperature compensation for analog optical data center interconnect applications is disclosed. The control loop can function in a stable manner because the electronics and optical components are monolithically integrated on a single substrate in small form factor. Because of the small size enabled by monolithic integration, the temperatures of the optical blocks and electronics blocks are tightly coupled, and the control loop time delays and phase delays are small enough to be stable, even for very high frequency operation. This arrangement enables a low cost, low power analog transmitter implementation for data center optical interconnect applications using advanced modulation schemes, such as PAM-4 and DP-QPSK.

Electro-absorption modulator with integrated control loop for linearization and temperature compensation

An integrated high speed electro-optical control loop for very high-speed linearization and temperature compensation of an electro-absorption modulator (EAM) for analog optical data center interconnect applications is disclosed. The control loop can function in a stable manner because the electronics and optical components are monolithically integrated on a single substrate in small form factor. Because of the small size enabled by monolithic integration, the temperatures of the optical blocks and electronics blocks are tightly coupled, and the control loop time delays and phase delays are small enough to be stable, even for very high frequency operation. This arrangement enables a low cost, low power analog transmitter implementation for data center optical interconnect applications using advanced modulation schemes, such as PAM-4 and DP-QPSK.

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Ottawa, Canada

William A Hagley