11. STOCK-BASED COMPENSATION - Stock-based compensation expense (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2024 |
|
| Stock-based compensation expense by line item | |||
| Stock-based compensation expense | $ 2,803,000 | $ 2,262,000 | $ 2,838,000 |
| Cost of revenues | |||
| Stock-based compensation expense by line item | |||
| Stock-based compensation expense | 231,000 | 199,000 | 228,000 |
| Research and development | |||
| Stock-based compensation expense by line item | |||
| Stock-based compensation expense | 945,000 | 1,010,000 | 1,411,000 |
| Selling, general and administrative | |||
| Stock-based compensation expense by line item | |||
| Stock-based compensation expense | 1,627,000 | 1,053,000 | 1,199,000 |
| Employee Stock Purchase Plan Year 2007 | |||
| Stock-based compensation expense by line item | |||
| Stock-based compensation expense | $ 163,000 | $ 176,000 | $ 230,000 |