Sycamore Networks today reported a loss for its 2007 fiscal year despite tremendous revenue growth. The optical switch vendor also announced the resignation of its chief financial officer, Richard Gaynor.

Gaynor, who joined Sycamore in 2004, has accepted a position elsewhere and will step down at the end of this month. The company is searching for a replacement.

In Sycamore’s 2007 fiscal year, which ended July 31, 2007, revenue grew 78% to $156 million. But the company reported a net loss of $13.2 million, or $0.05 per share, for the fiscal year, after reporting a net income of $19.4 million, or $0.07 per share, the prior year.

Eastern Research, the multiservice access vendor Sycamore acquired in the first quarter of the fiscal year, contributed $29.1 million, or about 42% of that annual growth. Excluding Eastern, Sycamore’s revenue grew 45%.

Revenue from Eastern Research’s products have fallen since before Sycamore acquired the company for $80 million in cash last year, a result Sycamore attributed today to decreased sales to two large Eastern Research customers, which have merged with each other. In the most recent quarter, Eastern’s products contributed $8.6 million in revenue, or less than 23% of total revenue. In the third quarter, Eastern’s contribution was 11%.

In July, Sycamore announced it was cutting 10% of its workforce.