Use of laser diodes in cavity ring-down spectroscopy

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:570216

Zare, R N; Paldus, B A; Ma, Y; Xie, J ^[1]

---

1. Stanford Univ., CA (United States)

We have demonstrated that cavity ring-down spectroscopy (CRDS), a highly sensitive absorption technique, is versatile enough to serve as a complete diagnostic for materials process control. In particular, we have used CRDS in the ultraviolet to determine the concentration profile of methyl radicals in a hot-filament diamond reactor; we have applied CRDS in the mid-infrared to detect 50 ppb of methane in a N{sub 2} environment; and, we have extended CRDS so that we can use continuous-wave diode laser sources. Using a laser diode at 810 nm, we were able to achieve a sensitivity of 2 x 10{sup -8} cm{sup -1}. Thus, CRDS can be used not only as an in situ diagnostic for investigating the chemistry of diamond film deposition, but it can also be used as a gas purity diagnostic for any chemical vapor deposition system.

• Research Organization: Argonne National Lab., IL (United States)
• DOE Contract Number: FG03-88ER13957
• OSTI ID: 570216
• Report Number(s): CONF-9705121--; ON: DE98000902
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
CHEMICAL ANALYSIS
CHEMICAL VAPOR DEPOSITION
FEEDBACK
LASER SPECTROSCOPY
LASERS
LIGHT EMITTING DIODES
PROCESS CONTROL