15. Stock-Based Compensation (Details-Stock-based compensation) - USD ($)  | 
12 Months Ended | |
|---|---|---|
Mar. 31, 2021  | 
Mar. 31, 2020  | 
|
| Total stock-based compensation | $ 371,000 | $ 839,000 | 
| Cost of revenues [Member] | ||
| Total stock-based compensation | (27,000) | 94,000 | 
| Research and development [Member] | ||
| Total stock-based compensation | 26,000 | 102,000 | 
| Selling, general and administrative [Member] | ||
| Total stock-based compensation | $ 372,000 | $ 643,000 | 
| X | ||||||||||
- Definition Amount of noncash expense for share-based payment arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
- Details 
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| X | ||||||||||
- Details 
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| X | ||||||||||
- Details 
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