Multiple micro-cavity laser with benzocyclobutene/semiconductor high reflective mirrors fabricated by CH4/H2-reactive ion etching

Multiple Micro-Cavity (MMC) lasers consisting of narrow and deep grooves buried with a Benzocyclobutene (BCB) polymer, were realized by the CH4/H-2-reactive ion etching (RIE) process. A threshold current of 30 mA was obtained at 200 K for the micro-cavity length l(H) = 5.1 mu m (groove width l(L) = 183 nm: pitch Lambda = 5.3 mu m, total cavity length L = 300 mu m, stripe width W-s = 5 mu m) while also showing a stable single-wavelength operation. Room temperature operation of an MMC laser consisting of 3 lambda/4-BCB buried grooves (= 0.70 mu m) was also obtained with a threshold current as low as 18 mA for the total cavity length of 200 mu m (Lambda = 20 mu m, 10 elements, W-s = 5 mu m), and the effective reflectivity of the MMC structure was estimated to be 94%.