Note 3 - Revenue Recognition - Revenue by Major Product Category (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Total Revenue	$ 54,189	$ 65,222	$ 103,890	$ 105,689
Percent of Revenue	100.00%	100.00%	100.00%	100.00%
Data Center [Member]
Total Revenue	$ 22,392	$ 52,533	$ 48,331	$ 85,797
Percent of Revenue	41.30%	80.50%	46.50%	81.20%
CATV [Member]
Total Revenue	$ 27,599	$ 6,141	$ 46,238	$ 10,364
Percent of Revenue	50.90%	9.40%	44.50%	9.80%
Telecom [Member]
Total Revenue	$ 3,333	$ 6,170	$ 7,811	$ 8,730
Percent of Revenue	6.20%	9.50%	7.50%	8.30%
FTTH [Member]
Total Revenue	$ 298	$ 1	$ 722	$ 1
Percent of Revenue	0.50%	0.00%	0.70%	0.00%
Product and Service, Other [Member]
Total Revenue	$ 567	$ 377	$ 788	$ 797
Percent of Revenue	1.00%	0.60%	0.80%	0.80%