We've taken great measures to ensure the safety of our employees and their families, and we are pleased to report that we are operating at 100% capacity and that our employees are well.
The information received from our staff during the Chinese New Year was very disconcerting as the virus was reported to be similar to the SARS virus of 2003.
Despite the challenges we faced, we demonstrated the flexibility inherent in our business model to produce financial results that were within our guidance range in our fiscal third quarter, with revenue of $411 million and non-GAAP net income of $0.92 per share.
Our high-level business mix was relatively consistent with our recent history, with 75% of revenue from optical communications and 25% from non-optical communications.
Optical communications revenue of 309 million was down 4% from the second quarter but up 3.5% from a year ago.
Within optical communications, telecom revenue was 224 million, down 10% from the second quarter but up 3% from a year ago, reflecting some inventory adjustments associated with certain next-generation programs.
Datacom revenue of 85 million rebounded nicely and was up 14% from the second quarter and up 5% from a year ago.
By technology, silicon photonics-based optical communications revenue increased 5%, both from the second quarter and from a year ago, to 86 million and represented 21% of total revenue.
Revenue from QSFP28 and QSFP56 transceivers also continued to grow and was up 7% from the second quarter and 17% from a year ago at 51 million or 12% of total revenue.
By data rate, 100-gig programs grew 1% from the second quarter and 10% from a year ago to 161 million.
Products rated at speeds of 400-gig and above declined 41% from the second quarter but grew 25% from a year ago to 29 million.
Revenue of 103 million was essentially flat from the second quarter and up 2% from a year ago.
Demand for industrial lasers was also flat sequentially with revenue of 46 million.
As such, automotive revenue was 31 million and other revenue was 22 million.
Sensor revenue was 3 million.
Because of this, we now expect our gross margin to be in the range of 11.5 to 12% or slightly below our target range of 12 to 12.5% for the full year.
More than 90% of our costs are variable, with components and materials making up the greatest portion of our costs.
From a balance sheet perspective, we remain very well capitalized with over $465 million in cash and investments and total debt of approximately $55 million.
Total revenue in the third quarter of fiscal year 2020 was 411.2 million, within our guidance range and slightly below our record second-quarter performance as anticipated.
Recall that in our last call, our revenue guidance incorporated an 8 million to $10 million impact from COVID-19.
During the quarter, we have demonstrated our extreme flexibility to produce financial results that were within our guidance changes even though the actual impact on revenue from the pandemic was 12 to $15 million or 4 to $5 million more than we originally anticipated.
Non-GAAP net income was $0.92 per share, which was at the lower end of our guidance range, even after the greater-than-expected effects on both revenue and expenses that Seamus discussed.
Combined with the revenue impact, gross margin was below our target range at 11.2% in the third quarter.
Non-GAAP operating expense was $12.2 million in the third quarter, flat with Q2.
As a result, non-GAAP operating income was 33.7 million, and non-GAAP operating margin was 8.2%.
Taxes in the third quarter were 1 million and our normalized effective tax rate was 2.4%.
With revenue streams coming from more advantageous tax jurisdiction, we now expect our effective tax rate to be below 5% for the full year.
Non-GAAP net income was 34.8 million in the third quarter or $0.92 per diluted share, as I indicated earlier.
On a GAAP basis, which includes share-based compensation expenses and amortization of debt issuance costs, net income for the third quarter was 28.3 million or $0.75 per diluted share, also within our guidance range.
At the end of the third quarter, cash, restricted cash and investments were 465.2 million, up from 450.5 million at the end of the second quarter.
Operating cash flow in the quarter was 51.8 million.
And with capex of $12.1 million, free cash flow was $29.8 million in the third quarter.
On a year-to-date basis, operating cash flow was 104.4 million and free cash flow was 77 million.
During the quarter, we repurchased 355,000 shares at an average price of $58.27 for a total cash outlay of 20.7 million.
At the end of the quarter, we have 41.5 million remaining in our share repurchase program.
That said, we are not immune from the broader factors that are impacting some of our customers, and this is reflected in our revenue guidance, which calls for a sequential decline of 6% at the midpoint.
For the fourth quarter, we anticipate revenue to be in the range of 370 to 400 million, including a 25 to 35 million impact from COVID-19-related uncertainties.
We are also reflecting in our guidance an approximately 15 million impact as a result of an inventory correction from one of our customers.
As you'd anticipate from the factors that impacted our gross margin in the third quarter, many of which will extend into upcoming quarters, we expect gross margin to be in the range of 11.5 to 12%, slightly below our target range of 12 to 12.5% for the full year of fiscal 2020.
From an earnings perspective, we anticipate non-GAAP net income per share in the fourth quarter to be in the range of $0.80 to $0.92 and GAAP net income per share of $0.64 to $0.76, based on approximately 27.6 million of fully diluted shares outstanding.

Summary:
Despite the challenges we faced, we demonstrated the flexibility inherent in our business model to produce financial results that were within our guidance range in our fiscal third quarter, with revenue of $411 million and non-GAAP net income of $0.92 per share.
Total revenue in the third quarter of fiscal year 2020 was 411.2 million, within our guidance range and slightly below our record second-quarter performance as anticipated.
Non-GAAP net income was $0.92 per share, which was at the lower end of our guidance range, even after the greater-than-expected effects on both revenue and expenses that Seamus discussed.
Non-GAAP net income was 34.8 million in the third quarter or $0.92 per diluted share, as I indicated earlier.
On a GAAP basis, which includes share-based compensation expenses and amortization of debt issuance costs, net income for the third quarter was 28.3 million or $0.75 per diluted share, also within our guidance range.
For the fourth quarter, we anticipate revenue to be in the range of 370 to 400 million, including a 25 to 35 million impact from COVID-19-related uncertainties.
From an earnings perspective, we anticipate non-GAAP net income per share in the fourth quarter to be in the range of $0.80 to $0.92 and GAAP net income per share of $0.64 to $0.76, based on approximately 27.6 million of fully diluted shares outstanding.