Gain Chip (GC) is the irreplaceable component as a gain medium for the building of the tunable diode laser or high stable external cavity diode laser. Gain Chip is similar to laser diode chip except the fact that it has deep antireflecting coating on one or both facets which significantly increases threshold of self lasing or eliminate it.
Typical external cavity diode laser configurations are Littrow-
Littrow / Littman
Innolume Gain Chip product line subdividing in two main categories:
1. One side optical access (Types A and B)
2. Two sides optical access (Types C and D)
One side optical access Gain Chip is ideal component for operation in the scheme where the output power is outcoupled from the external cavity. Typically they are supplied in TO-
Two sides optical access Gain Chip can be used in scheme allowing power outcoupling directly from the Gain Chip Facet to reduce the optical losses or in optical scheme for the amplification.
Type A Gain Chip has straight stripe normal to the facets with high reflecting (HR) and deep antireflecting (AR) coatings. This is the most cost effective solution for the building of the external cavity diode laser. Type A GC has symmetrical beam far field providing efficient coupling to the external cavity and back using high NA aspheric lens. This type of the Gain Chips has relatively low gain spectra ripples suppression compare to the other types. It results from the fact that the reflection of the AR coated facet is on the level of 0.1% and can be further reduced by using slanted stripe-
Type B GC has curved stripe with HR-
Type C GC has curved stripe and deep AR-
Type D GC has a tilted stripe with a deep AR on both sides, typically it used for the advanced optical schemes were the build-