We propose to develop the key components, i.e. from the optical crystals to the final instrument for a portable trace gas detector based on tunable laser sources. We plan to use mid-infrared narrow line width optical parametric oscillators in order to detect the strong absorption features many gas molecules have in this spectral region. Our approach is a vertically integrated one, with partners having expertise in optical crystal fabrication, in laser design and manufacturing, and in pollution monitoring. The two partners involved in crystal growth are SME's with a proven track record in the field. These two SME's will request a contribution from the EC for a feasibility study and a thorough phase 2 proposal planning phase. The partnership we have in mind will lead to a field-testable prototype and to novel state-of-the-art products at the component level. The feasibility study will already provide European laser manufacturers with new and improved solid state materials. The proposed programme will enable the two optical crystal growth SME's to propose new products with specifications required by the marketplace but previously not achievable.