Organic Polymer DBR Laser by Soft Lithography II: Optimization of Distributed Bragg Reflector

We describe detailed analysis and optimization of the photopumped organic polymer distributed Bragg reflector laser having polymer grating fabricated using a replica molding method, which is an imprinting technology often called “soft lithography”, whose advantage is much less damage to materials. After the optimization, the laser oscillation threshold of only 0.6 μJ/cm2 was achieved. This threshold is comparable to that of organic DFB lasers with a quartz grating precisely fabricated using photolithography and dry etching. While glass was used as a substrate in this study, plastic substrates are also available. In near future, flexible low-threshold organic laser will be demonstrated.