Shares of Applied Optoelectronics Inc. are down 8.1% in premarket trading after the company reported weaker-than-expected earnings and revenue for its March quarter. "The light quarter was blamed on staff turn-over in China," wrote Raymond James analyst Simon Leopold, who kept his strong buy rating on the stock and raised his price target to $51 from $50. Still, he sees "plenty of reasons for optimism," including management's projection that demand for 100G products will more than double in the second half of the year. Needham's Alex Henderson also defended his strong buy rating, writing that "normalizing data comm inventory is encouraging." He has a $40 price target on the stock. DA Davidson analyst Mark Kelleher wrote that Applied Optoelectronics saw three of its customers each make up more than 10% of total revenue during the quarter, which were likely Amazon.com Inc. Microsoft Corp. and Facebook Inc. He kept his buy rating and $50 price target intact. Applied Opto shares were down 43% over the past 12 months, as of Tuesday's close, while the S&P 500 had gained 11%.