MINNEAPOLIS, Oct. 17 -- Over the last month APA Optics Inc. has received more than 10 purchase orders for its dense wavelength division multiplexing products -- about $265,000 in potential sales -- bringing the company's four-month total in sales to about $500,000, said APA Optics. Orders for the DWDM systems have ranged from one to eight units. These recent orders are significant to APA because they demonstrate a broadening interest in our DWDM products, with several new customers purchasing units for evaluation and orders from two repeat customers said Anil Jain, APA's president and CEO. A significant portion of these orders are for our 56-channel DWDM units, where we believe the advantages of our patented bulk diffraction grating technology for higher channel counts is demonstrated.