To make the post installation test for the optical isolation of the OFI, a fiber coupled beam launcher was constructed. It consists of two portable breadboards connected with a PM-SM fiber.

The first attachment (input_table.jpg) shows the source part. This table is placed at a chamber side. An NPRO is mounted on the table and mode matched to a fiber coupler via a f=50mm lens. The max incident power to the fiber is about 100mW and the coupling efficiency was measured to be 81% max.

The second attachment (launcher.jpg) shows the beam launching part. This table is placed on the HAM6 ISI table. As the OFI is placed at the edge of the HAM5 table, we need to shoot the beam from HAM6 at the optical height of 4". The components on this table have been cleaned to be (at least) CLASS B. The output beam is converted to a thick beam with a f=100mm lens. The output mode is measured with Mode Master (the third attachment). It shows the Rayleigh range of ~3m. i.e. The beam radius is ~1mm and is intentionally smaller  (about a half) than the PSL beam size there to make the in-situ measurement easier.

They are transported to the HAM6 side this morning. The laser power supply is connected to an interlock-enabled power extension laid out from SQZ Bay. We also have the local kill switch.