Document and Entity Information	3 Months Ended
	Mar. 31, 2013	Apr. 30, 2013
Document Information [Line Items]
Document Type	10-Q/A
Amendment Flag	true
Amendment Description	NeoPhotonics Corporation (the “Company”), is filing this Amendment No. 2 to its Quarterly Report on Form 10-Q (“Amendment No. 2”) to restate and amend the Company’s previously issued and unaudited interim financial statements and related financial information as of March 31, 2013 and for the three months ended March 31, 2013, which was originally filed with the Securities and Exchange Commission (the “SEC”) on May 15, 2013 and subsequently amended in Amendment No. 1 (“Amendment No. 1”) filed with the SEC on August 8, 2013. Amendment No. 1 was filed to adjust the Company’s consolidated statement of cash flows for the three months ended March 31, 2013 for amounts related to purchases of property and equipment that were overstated. As disclosed in the Company’s Current Report on Form 8-K filed with the SEC on November 14, 2013, the Company determined that its unaudited condensed consolidated financial statements for the three months ended March 31, 2013 contained an error related to its accounting for a real estate registration tax which was incorrectly reflected as a component of the property, plant and equipment acquired as part of the purchase of NeoPhotonics Semiconductor (formerly the Optical Component Unit of LAPIS Semiconductor (“OCI”)). In addition, the Company has made other corrections related to the purchase of NeoPhotonics Semiconductor, classification of certain amounts and other corrections, all of which were discovered during the close of its September 30, 2013 accounting records. For further information regarding the restatement, see Note 2 of the Notes to the Condensed Consolidated Financial Statements. Because of the corrections described above, management re-evaluated the Company’s control environment and concluded that additional material weaknesses existed at March 31, 2013 as more fully described in Item 4 “Controls and Procedures” in this Amendment No. 2. Consistent with the information described above, the Company has revised the following items in this Amendment No. 2: Part I Item 1- Condensed Consolidated Financial Statements Item 2 – Management’s Discussion and Analysis of Financial Condition and Results of Operations Item 4 – Controls and Procedures Part II Item 1A- Risk Factors Additionally, in this Amendment No. 2, the Company is including currently dated certifications from the Company’s Principal Executive Officer and Principal Financial Officer as required by Section 302 of the Sarbanes-Oxley Act of 2002 in Exhibits 31.1 and 31.2 and a currently dated certification from the Company’s Principal Executive Officer and Principal Financial Officer as required by Section 906 of the Sarbanes-Oxley Act of 2002 in Exhibit 32.1. Except to the extent described above and set forth herein, the items and other disclosures in the Form 10-Q initially filed on May 15, 2013 (the “initial Form 10-Q”) as previously amended by Amendment No. 1 are unchanged and this Amendment No. 2 does not reflect any events that have occurred after the initial Form 10-Q was filed. Accordingly, this Amendment No. 2 should be read in conjunction with the Company’s initial Form 10-Q (as amended by Amendment No. 1) and the Company’s subsequent filings with the United States Securities and Exchange Commission. In light of the restatement, readers should not rely on the Company’s previously filed financial statements as of and for the three month period ended March 31, 2013.
Document Period End Date	Mar. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	Q1
Trading Symbol	NPTN
Entity Registrant Name	NEOPHOTONICS CORP
Entity Central Index Key	0001227025
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		30,611,417