Embodiments include a reaction vessel having a first reaction chamber filled with a first material; a first light absorbing region adhered to an interior-facing surface of the first reaction chamber; a second reaction chamber filled with a second material; a second light absorbing region adhered to an interior-facing surface of the second reaction chamber; a temperature sensor disposed within the second reaction chamber; and one or more energy sources configured to direct light at the first light absorbing region and the second light absorbing region. A processor may be employed to determine a first temperature of the first material from a second temperature of the second material measured by the temperature sensor. Methods of manufacturing such a reaction vessel are also disclosed.