  We introduce an analytical model for ideal organic laser diodes based on the
argument that their intrinsic active layers necessitate operation in the
bipolar space charge-limited current regime. Expressions for the threshold
current and voltage agree well with drift-diffusion modeling of complete p-i-n
devices and an analytical bound is established for laser operation in the
presence of annihilation and excited-state absorption losses. These results
establish a foundation for the development of organic laser diode technology.
