| 8. Stock-Based Compensation (Details - Allocated Share-Based Compensation Expense) (USD $) | 3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Total stock-based compensation | $ 456,000 | $ 296,000 | $ 907,000 | $ 483,000 | 
| Cost of revenues [Member] | ||||
| Total stock-based compensation | 59,000 | 30,000 | 123,000 | 56,000 | 
| Research and development [Member] | ||||
| Total stock-based compensation | 82,000 | 45,000 | 178,000 | 78,000 | 
| Selling, general and administrative [Member] | ||||
| Total stock-based compensation | $ 315,000 | $ 221,000 | $ 606,000 | $ 349,000 |