Description of Business	12 Months Ended
Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	NOTE 1.Description of Business Business Overview EMCORE Corporation (referred to herein, together with its subsidiaries, as the “Company,” “we,” “our,” or “EMCORE”) was established in 1984 as a New Jersey corporation. The Company became publicly traded in 1997 and is listed on the Nasdaq stock exchange under the ticker symbol EMKR. EMCORE is a leading provider of sensors for navigation in the Aerospace and Defense market as well as a manufacturer of lasers and optical subsystems for use in the cable TV industry. EMCORE pioneered the linear fiber optic transmission technology that enabled the world’s first delivery of Cable TV directly on fiber, and today is a leading provider of advanced Mixed-Signal Optics products that enable communications systems and service providers to meet growing demand for increased bandwidth and connectivity. The Mixed-Signal Optics technology at the heart of our broadband communications products is shared with our fiber optic gyros and inertial sensors to provide the aerospace and defense markets with state-of-the-art navigation systems technology. With the acquisition of Systron Donner Inertial, Inc. (“SDI”), a navigation systems provider with a scalable, chip-based platform for higher volume gyro applications utilizing Quartz MEMS technology, in June 2019, EMCORE further expanded its portfolio of gyros and inertial sensors with SDI’s quartz MEMS gyro and accelerometer technology. EMCORE has fully vertically-integrated manufacturing capability through our indium phosphide compound semiconductor wafer fabrication facility at our headquarters in Alhambra, CA, and through our quartz processing and sensor manufacturing facility in Concord, CA. These facilities support EMCORE’s vertically-integrated manufacturing strategy for quartz and fiber optic gyro products, for navigation systems, and for our chip, laser, transmitter, and receiver products for broadband applications. With both analog and digital circuits on multiple chips, or even a single chip, the value of Mixed-Signal device solutions are often far greater than traditional digital applications and requires a specialized expertise held by EMCORE which is unique in the optics industry. We have two reporting segments, Aerospace and Defense, and Broadband. Aerospace and Defense is comprised of two product lines: (i) Navigation and Inertial Sensing, and (ii) Defense Optoelectronics. The Broadband segment is comprised of three product lines: (i) CATV Lasers and Transmitters, (ii) Chip Devices, and (iii) Other. Due to a shift in customer base, the previously existing Satellite/Microwave Communications product line has been renamed “Defense Optoelectronics.”

Description of Business

12 Months Ended

Sep. 30, 2020

Organization, Consolidation and Presentation of Financial Statements [Abstract]

NOTE 1.Description of Business

Business Overview

EMCORE Corporation (referred to herein, together with its subsidiaries, as the “Company,” “we,” “our,” or “EMCORE”) was established in 1984 as a New Jersey corporation. The Company became publicly traded in 1997 and is listed on the Nasdaq stock exchange under the ticker symbol EMKR. EMCORE is a leading provider of sensors for navigation in the Aerospace and Defense market as well as a manufacturer of lasers and optical subsystems for use in the cable TV industry. EMCORE pioneered the linear fiber optic transmission technology that enabled the world’s first delivery of Cable TV directly on fiber, and today is a leading provider of advanced Mixed-Signal Optics products that enable communications systems and service providers to meet growing demand for increased bandwidth and connectivity. The Mixed-Signal Optics technology at the heart of our broadband communications products is shared with our fiber optic gyros and inertial sensors to provide the aerospace and defense markets with state-of-the-art navigation systems technology. With the acquisition of Systron Donner Inertial, Inc. (“SDI”), a navigation systems provider with a scalable, chip-based platform for higher volume gyro applications utilizing Quartz MEMS technology, in June 2019, EMCORE further expanded its portfolio of gyros and inertial sensors with SDI’s quartz MEMS gyro and accelerometer technology. EMCORE has fully vertically-integrated manufacturing capability through our indium phosphide compound semiconductor wafer fabrication facility at our headquarters in Alhambra, CA, and through our quartz processing and sensor manufacturing facility in Concord, CA. These facilities support EMCORE’s vertically-integrated manufacturing strategy for quartz and fiber optic gyro products, for navigation systems, and for our chip, laser, transmitter, and receiver products for broadband applications. With both analog and digital circuits on multiple chips, or even a single chip, the value of Mixed-Signal device solutions are often far greater than traditional digital applications and requires a specialized expertise held by EMCORE which is unique in the optics industry.

We have two reporting segments, Aerospace and Defense, and Broadband. Aerospace and Defense is comprised of two product lines: (i) Navigation and Inertial Sensing, and (ii) Defense Optoelectronics. The Broadband segment is comprised of three product lines: (i) CATV Lasers and Transmitters, (ii) Chip Devices, and (iii) Other. Due to a shift in customer base, the previously existing Satellite/Microwave Communications product line has been renamed “Defense Optoelectronics.”