By shaping the metal electrodes on the upper and lower sides of the laser, the region where current passes is limited.
The spatial shape of current flow causes selective pumping. As a result, population inversion occurs only at the specific region where current passes.

An example is shown in figure 6.28, where a narrow stripe shaped electrode is on top of the laser. The current limits the area in the active region where amplification can occur. Only in this region light will be amplified.

Advantages of gain guided diode lasers:

1. Simple production.
2. It is simple to get high power, since by increasing the current, the region where amplification occurs expands.

Disadvantages of gain guided diode lasers:

1. Output beam quality is less than with index guided lasers.
2. It is more difficult to achieve stable single frequency out of these lasers.