1. Begin with a new file, 300×300, and with a transparent background. Now make sure you have black as your foreground color, and white as your background color. Then take the Gradient Tool and make these settings.

2. Then draw some vertical lines. ( Click for larger view )

3. Now go to Filter>Stylize>Find Edges. ( Click for larger view )

4. Then press Ctrl+I. ( Click for larger view )

5. Now press Ctrl+U, and make these settings.

Click OK, and you’re done! This is what I came up with.