Harmonic Inc. HLIT shares jumped by more than 10% during the extended session on Monday, after the manufacturer of fiber-optic systems and other telecommunications products reported adjusted quarterly earnings that were better than expected and revenue close to Wall Street forecast. Harmonic’s first-quarter earnings were $5.1 million or 4 cents per share. This is a huge turnaround from the $1.5 million loss, or 1 penny per share, it suffered in the previous quarter. After adjusting for one-time expenses, Harmonic earned 12 cents per share. The company’s revenue increased 7%, to $157.6 millions. This was due to “strong demand” of its products. FactSet polled analysts who expected adjusted earnings…