Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Indemnifications We have agreed to indemnify certain customers against claims of infringement of intellectual property rights of others in our sales contracts with these customers. Historically, we have not paid any claims under these customer indemnification obligations. We enter into indemnification agreements with each of our directors and executive officers pursuant to which we agree to indemnify them for certain potential expenses and liabilities arising from their status as a director or executive officer of the Company. We maintain directors and officers insurance, which covers certain liabilities relating to our obligation to indemnify our directors and executive officers in certain circumstances. It is not possible to determine the aggregate maximum potential loss under these indemnification agreements due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular claim. Legal Proceedings We are subject to various legal proceedings, claims, and litigation, either asserted or unasserted, that arise in the ordinary course of business. The outcome of these matters is currently not determinable and we are unable to estimate a range of loss, should a loss occur, from these proceedings. The ultimate outcome of legal proceedings involves judgments, estimates, and inherent uncertainties and the results of these matters cannot be predicted with certainty. Professional legal fees are expensed when incurred. We accrue for contingent losses when such losses are probable and reasonably estimable. In the event that estimates or assumptions prove to differ from actual results, adjustments are made in subsequent periods to reflect more current information. Should we fail to prevail in any legal matter, or should several legal matters be resolved against the Company in the same reporting period, then the financial results of that particular reporting period could be materially affected. Intellectual Property Lawsuits We protect our proprietary technology by applying for patents where appropriate and, in other cases, by preserving the technology, related know-how, and information as trade secrets. The success and competitive position of our product lines are impacted by our ability to obtain intellectual property protection for our research and development efforts. We have, from time to time, exchanged correspondence with third parties regarding the assertion of patent or other intellectual property rights in connection with certain of our products and processes. Resilience Litigation In February 2021, Resilience Capital (“Resilience”) filed a complaint against us with the Delaware Chancery Court containing claims arising from the February 2020 sale of SDI’s real property (the “Concord Property Sale”) located in Concord, California (the “Concord Real Property”) to Eagle Rock Holdings, LP (“Buyer”) and that certain Single-Tenant Triple Net Lease, dated as of February 10, 2020, entered into by and between SDI and the Buyer, pursuant to which SDI leased from the Buyer the Concord Real Property for a 15-year term. The Resilience complaint seeks, among other items, (a) a declaration that the Concord Property Sale included a non-cash component, (b) a decree requiring us and Resilience to follow the appraisal requirements set forth in that certain Purchase and Sale Agreement (the “SDI Purchase Agreement”), dated as of June 7, 2019, by and among the Company, The Resilience Fund IV, L.P., The Resilience Fund IV-A, L.P., Aerospace Newco Holdings, Inc. and Ember Acquisition Sub, Inc., (c) recovery of Resilience’s costs and expenses, and (d) pre- and post-judgment interest. In April 2021, we filed with the Delaware Chancery Court our answer to the Resilience complaint and counterclaims against Resilience, in which we are seeking, among other items, (a) dismissal of the Resilience complaint and/or granting of judgment in favor of EMCORE with respect to the Resilience complaint, (b) entering final judgment against Resilience awarding damages to us for Resilience’s fraud and breaches of the SDI Purchase Agreement in an amount to be proven at trial and not less than $1,565,000, (c) a judicial determination of the respective rights and duties of us and Resilience under the SDI Purchase Agreement, (d) an award to us of costs and expenses, and (e) pre- and post-judgment interest. On April 24, 2023, the Company and Resilience entered into a Settlement and Release Agreement (the “Resilience Settlement Agreement”). The material financial terms of the Resilience Settlement Agreement required (i) a payment of $500,000 by the Company to Resilience, which payment was made by the Company during the three months ended June 30, 2023, (ii) an appraisal of the Concord Real Property as of January 2, 2020, which could trigger a further future payment by the Company in an amount to be determined by said appraisal, and if triggered, is expected to be made during the three months ending September 30, 2023, and (iii) a mutual release of all claims, including claims arising under the SDI Purchase Agreement, and a dismissal of the litigation by all parties. On April 24, 2023, the underwriters of the representation and warranty insurance policies the Company acquired in connection with the SDI Purchase Agreement agreed to pay the Company $1.15 million within 15 business days in exchange for a release of any and all claims under the policies. We received payment during the three months ended June 30, 2023. Contingent Inventory Obligations Pursuant to that certain Manufacturing Supply Agreement, dated August 9, 2021 (as amended, the “Fastrain Manufacturing Agreement”), by and between the Company and each of Shenzhen Fastrain Technology Co., Ltd., Hong Kong Fastrain Company Limited and Fastrain Technology Malaysia SDN. BHD. (collectively, “Fastrain”), we may be liable to Fastrain for certain unused inventory. As of the quarter ended June 30, 2023, we had accrued $0.4 million pursuant to such inventory obligations in connection with our restructuring announced in April 2023 and estimate a potential range of total future additional liability pursuant to such inventory obligations of a minimum of $0 and a maximum of $3.2 million.